500 Error when Relationship field lists entries from mixed collections

[PieterjanNeskensCVOVolt]

Bug description

I have a Link field with multiple manually selected collections it can link to.
When I go and select an entry it should display a list of all entries across the configured collections.
I don't get the list, I get a 500 server error: foreach() argument must be of type array|object, string given at ../tiptap-php/src/Core/DOMSerializer.php:64
This happens because I have multiple field, of different fieldtypes, with handle 'content' across collections.

See 'additional details' for an AI generated explanation why this bug happens.

How to reproduce

GitHub repo: https://github.com/PieterjanNeskensCVOVolt/statamic-bug

Or these very specific steps:

1. Create 2 collections (News and Blog in this example)
2. In the News blueprint, add a Bard field with handle 'content' with 2 sets inside.
3. In the Blog blueprint, add a Replicator field with handle 'content' with 2 sets inside. In 1 set add a Textarea field with handle 'content'.
4. In the Pages blueprint, add a Link field and select the News and Blog (in this order) collection as collection to choose entries from.
5. Create a News entry with title 'test entry' and add some sets to the content bard field.
6. Create a Blog entry with title '1 test entry' (the number makes sure this entry is shown first in a list) and add some sets to the content replicator field. Make sure that the set with the Textarea field with handle 'content' has some content inside.
7. Go to a Page entry and select 'entry' in the link field.

Logs

local.ERROR: Call to a member function entryClass() on null {"userId":"d9e1a9b1-214f-430f-9c71-2403569f94f9","exception":"[object] (Error(code: 0): Call to a member function entryClass() on null at /var/www/html/vendor/statamic/cms/src/Entries/Entry.php:158)
[stacktrace]
#0 /var/www/html/vendor/statamic/cms/src/Stache/Stores/CollectionEntriesStore.php(73): Statamic\\Entries\\Entry->collection()
#1 /var/www/html/vendor/statamic/cms/src/Stache/Stores/Store.php(314): Statamic\\Stache\\Stores\\CollectionEntriesStore->makeItemFromFile()
#2 [internal function]: Statamic\\Stache\\Stores\\Store->{closure:Statamic\\Stache\\Stores\\Store::paths():312}()
#3 /var/www/html/vendor/laravel/framework/src/Illuminate/Collections/Arr.php(841): array_map()
#4 /var/www/html/vendor/laravel/framework/src/Illuminate/Collections/Collection.php(815): Illuminate\\Support\\Arr::map()
#5 /var/www/html/vendor/statamic/cms/src/Stache/Stores/Store.php(312): Illuminate\\Support\\Collection->map()
#6 /var/www/html/vendor/statamic/cms/src/Stache/Stores/Store.php(219): Statamic\\Stache\\Stores\\Store->paths()
#7 /var/www/html/vendor/statamic/cms/src/Stache/Stores/Store.php(300): Statamic\\Stache\\Stores\\Store->handleFileChanges()
#8 /var/www/html/vendor/statamic/cms/src/Stache/Duplicates.php(88): Statamic\\Stache\\Stores\\Store->paths()
#9 /var/www/html/vendor/laravel/framework/src/Illuminate/Collections/Traits/EnumeratesValues.php(275): Statamic\\Stache\\Duplicates->{closure:Statamic\\Stache\\Duplicates::find():86}()
#10 /var/www/html/vendor/statamic/cms/src/Stache/Duplicates.php(86): Illuminate\\Support\\Collection->each()
#11 /var/www/html/vendor/statamic/cms/src/Http/Controllers/CP/DuplicatesController.php(26): Statamic\\Stache\\Duplicates->find()
#12 /var/www/html/vendor/statamic/cms/src/Http/Controllers/CP/DuplicatesController.php(19): Statamic\\Http\\Controllers\\CP\\DuplicatesController->getDuplicates()
#13 /var/www/html/vendor/laravel/framework/src/Illuminate/Routing/Controller.php(54): Statamic\\Http\\Controllers\\CP\\DuplicatesController->index()
#14 /var/www/html/vendor/laravel/framework/src/Illuminate/Routing/ControllerDispatcher.php(43): Illuminate\\Routing\\Controller->callAction()
#15 /var/www/html/vendor/laravel/framework/src/Illuminate/Routing/Route.php(269): Illuminate\\Routing\\ControllerDispatcher->dispatch()
#16 /var/www/html/vendor/laravel/framework/src/Illuminate/Routing/Route.php(215): Illuminate\\Routing\\Route->runController()
#17 /var/www/html/vendor/laravel/framework/src/Illuminate/Routing/Router.php(822): Illuminate\\Routing\\Route->run()
#18 /var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(180): Illuminate\\Routing\\Router->{closure:Illuminate\\Routing\\Router::runRouteWithinStack():821}()
#19 /var/www/html/vendor/statamic/cms/src/Http/Middleware/CP/HandleAuthenticatedInertiaRequests.php(24): Illuminate\\Pipeline\\Pipeline->{closure:Illuminate\\Pipeline\\Pipeline::prepareDestination():178}()
#20 /var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(219): Statamic\\Http\\Middleware\\CP\\HandleAuthenticatedInertiaRequests->handle()
#21 /var/www/html/vendor/statamic/cms/src/Http/Middleware/DeleteTemporaryFileUploads.php(18): Illuminate\\Pipeline\\Pipeline->{closure:{closure:Illuminate\\Pipeline\\Pipeline::carry():194}:195}()
#22 /var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(219): Statamic\\Http\\Middleware\\DeleteTemporaryFileUploads->handle()
#23 /var/www/html/vendor/statamic/cms/src/Http/Middleware/RedirectIfTwoFactorSetupIncomplete.php(23): Illuminate\\Pipeline\\Pipeline->{closure:{closure:Illuminate\\Pipeline\\Pipeline::carry():194}:195}()
#24 /var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(219): Statamic\\Http\\Middleware\\RedirectIfTwoFactorSetupIncomplete->handle()
#25 /var/www/html/vendor/statamic/cms/src/Http/Middleware/CP/AddVaryHeaderToResponse.php(11): Illuminate\\Pipeline\\Pipeline->{closure:{closure:Illuminate\\Pipeline\\Pipeline::carry():194}:195}()
#26 /var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(219): Statamic\\Http\\Middleware\\CP\\AddVaryHeaderToResponse->handle()
#27 /var/www/html/vendor/statamic/cms/src/Http/Middleware/CP/CountUsers.php(18): Illuminate\\Pipeline\\Pipeline->{closure:{closure:Illuminate\\Pipeline\\Pipeline::carry():194}:195}()
#28 /var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(219): Statamic\\Http\\Middleware\\CP\\CountUsers->handle()
#29 /var/www/html/vendor/statamic/cms/src/Http/Middleware/CP/BootUtilities.php(14): Illuminate\\Pipeline\\Pipeline->{closure:{closure:Illuminate\\Pipeline\\Pipeline::carry():194}:195}()
#30 /var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(219): Statamic\\Http\\Middleware\\CP\\BootUtilities->handle()
#31 /var/www/html/vendor/statamic/cms/src/Http/Middleware/CP/BootPreferences.php(14): Illuminate\\Pipeline\\Pipeline->{closure:{closure:Illuminate\\Pipeline\\Pipeline::carry():194}:195}()
#32 /var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(219): Statamic\\Http\\Middleware\\CP\\BootPreferences->handle()
#33 /var/www/html/vendor/statamic/cms/src/Http/Middleware/CP/BootPermissions.php(14): Illuminate\\Pipeline\\Pipeline->{closure:{closure:Illuminate\\Pipeline\\Pipeline::carry():194}:195}()
#34 /var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(219): Statamic\\Http\\Middleware\\CP\\BootPermissions->handle()
#35 /var/www/html/vendor/statamic/cms/src/Http/Middleware/CP/SelectedSite.php(17): Illuminate\\Pipeline\\Pipeline->{closure:{closure:Illuminate\\Pipeline\\Pipeline::carry():194}:195}()
#36 /var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(219): Statamic\\Http\\Middleware\\CP\\SelectedSite->handle()
#37 /var/www/html/vendor/statamic/cms/src/Http/Middleware/CP/Authorize.php(24): Illuminate\\Pipeline\\Pipeline->{closure:{closure:Illuminate\\Pipeline\\Pipeline::carry():194}:195}()
#38 /var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(219): Statamic\\Http\\Middleware\\CP\\Authorize->handle()
#39 /var/www/html/vendor/statamic/cms/src/Http/Middleware/CP/Localize.php(39): Illuminate\\Pipeline\\Pipeline->{closure:{closure:Illuminate\\Pipeline\\Pipeline::carry():194}:195}()
#40 /var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(219): Statamic\\Http\\Middleware\\CP\\Localize->handle()
#41 /var/www/html/vendor/laravel/framework/src/Illuminate/Foundation/Http/Middleware/TransformsRequest.php(21): Illuminate\\Pipeline\\Pipeline->{closure:{closure:Illuminate\\Pipeline\\Pipeline::carry():194}:195}()
#42 /var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(219): Illuminate\\Foundation\\Http\\Middleware\\TransformsRequest->handle()
#43 /var/www/html/vendor/statamic/cms/src/Http/Middleware/CP/AddToasts.php(22): Illuminate\\Pipeline\\Pipeline->{closure:{closure:Illuminate\\Pipeline\\Pipeline::carry():194}:195}()
#44 /var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(219): Statamic\\Http\\Middleware\\CP\\AddToasts->handle()
#45 /var/www/html/vendor/statamic/cms/src/Http/Middleware/CP/AuthGuard.php(14): Illuminate\\Pipeline\\Pipeline->{closure:{closure:Illuminate\\Pipeline\\Pipeline::carry():194}:195}()
#46 /var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(219): Statamic\\Http\\Middleware\\CP\\AuthGuard->handle()
#47 /var/www/html/vendor/statamic/cms/src/Http/Middleware/CP/ContactOutpost.php(21): Illuminate\\Pipeline\\Pipeline->{closure:{closure:Illuminate\\Pipeline\\Pipeline::carry():194}:195}()
#48 /var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(219): Statamic\\Http\\Middleware\\CP\\ContactOutpost->handle()
#49 /var/www/html/vendor/laravel/framework/src/Illuminate/Routing/Middleware/SubstituteBindings.php(52): Illuminate\\Pipeline\\Pipeline->{closure:{closure:Illuminate\\Pipeline\\Pipeline::carry():194}:195}()
#50 /var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(219): Illuminate\\Routing\\Middleware\\SubstituteBindings->handle()
#51 /var/www/html/vendor/laravel/framework/src/Illuminate/Session/Middleware/AuthenticateSession.php(70): Illuminate\\Pipeline\\Pipeline->{closure:{closure:Illuminate\\Pipeline\\Pipeline::carry():194}:195}()
#52 /var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(219): Illuminate\\Session\\Middleware\\AuthenticateSession->handle()
#53 /var/www/html/vendor/inertiajs/inertia-laravel/src/Middleware.php(122): Illuminate\\Pipeline\\Pipeline->{closure:{closure:Illuminate\\Pipeline\\Pipeline::carry():194}:195}()
#54 /var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(219): Inertia\\Middleware->handle()
#55 /var/www/html/vendor/laravel/framework/src/Illuminate/Foundation/Http/Middleware/PreventRequestForgery.php(104): Illuminate\\Pipeline\\Pipeline->{closure:{closure:Illuminate\\Pipeline\\Pipeline::carry():194}:195}()
#56 /var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(219): Illuminate\\Foundation\\Http\\Middleware\\PreventRequestForgery->handle()
#57 /var/www/html/vendor/laravel/framework/src/Illuminate/View/Middleware/ShareErrorsFromSession.php(48): Illuminate\\Pipeline\\Pipeline->{closure:{closure:Illuminate\\Pipeline\\Pipeline::carry():194}:195}()
#58 /var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(219): Illuminate\\View\\Middleware\\ShareErrorsFromSession->handle()
#59 /var/www/html/vendor/laravel/framework/src/Illuminate/Session/Middleware/StartSession.php(120): Illuminate\\Pipeline\\Pipeline->{closure:{closure:Illuminate\\Pipeline\\Pipeline::carry():194}:195}()
#60 /var/www/html/vendor/laravel/framework/src/Illuminate/Session/Middleware/StartSession.php(63): Illuminate\\Session\\Middleware\\StartSession->handleStatefulRequest()
#61 /var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(219): Illuminate\\Session\\Middleware\\StartSession->handle()
#62 /var/www/html/vendor/laravel/framework/src/Illuminate/Cookie/Middleware/AddQueuedCookiesToResponse.php(36): Illuminate\\Pipeline\\Pipeline->{closure:{closure:Illuminate\\Pipeline\\Pipeline::carry():194}:195}()
#63 /var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(219): Illuminate\\Cookie\\Middleware\\AddQueuedCookiesToResponse->handle()
#64 /var/www/html/vendor/laravel/framework/src/Illuminate/Cookie/Middleware/EncryptCookies.php(74): Illuminate\\Pipeline\\Pipeline->{closure:{closure:Illuminate\\Pipeline\\Pipeline::carry():194}:195}()
#65 /var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(219): Illuminate\\Cookie\\Middleware\\EncryptCookies->handle()
#66 /var/www/html/vendor/statamic/cms/src/Http/Middleware/SwapExceptionHandler.php(19): Illuminate\\Pipeline\\Pipeline->{closure:{closure:Illuminate\\Pipeline\\Pipeline::carry():194}:195}()
#67 /var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(219): Statamic\\Http\\Middleware\\SwapExceptionHandler->handle()
#68 /var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(137): Illuminate\\Pipeline\\Pipeline->{closure:{closure:Illuminate\\Pipeline\\Pipeline::carry():194}:195}()
#69 /var/www/html/vendor/laravel/framework/src/Illuminate/Routing/Router.php(821): Illuminate\\Pipeline\\Pipeline->then()
#70 /var/www/html/vendor/laravel/framework/src/Illuminate/Routing/Router.php(800): Illuminate\\Routing\\Router->runRouteWithinStack()
#71 /var/www/html/vendor/laravel/framework/src/Illuminate/Routing/Router.php(764): Illuminate\\Routing\\Router->runRoute()
#72 /var/www/html/vendor/laravel/framework/src/Illuminate/Routing/Router.php(753): Illuminate\\Routing\\Router->dispatchToRoute()
#73 /var/www/html/vendor/laravel/framework/src/Illuminate/Foundation/Http/Kernel.php(200): Illuminate\\Routing\\Router->dispatch()
#74 /var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(180): Illuminate\\Foundation\\Http\\Kernel->{closure:Illuminate\\Foundation\\Http\\Kernel::dispatchToRouter():197}()
#75 /var/www/html/vendor/statamic/cms/src/Http/Middleware/StopImpersonating.php(13): Illuminate\\Pipeline\\Pipeline->{closure:Illuminate\\Pipeline\\Pipeline::prepareDestination():178}()
#76 /var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(219): Statamic\\Http\\Middleware\\StopImpersonating->handle()
#77 /var/www/html/vendor/statamic/cms/src/Http/Middleware/CheckMultisite.php(15): Illuminate\\Pipeline\\Pipeline->{closure:{closure:Illuminate\\Pipeline\\Pipeline::carry():194}:195}()
#78 /var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(219): Statamic\\Http\\Middleware\\CheckMultisite->handle()
#79 /var/www/html/vendor/statamic/cms/src/Http/Middleware/CheckComposerJsonScripts.php(21): Illuminate\\Pipeline\\Pipeline->{closure:{closure:Illuminate\\Pipeline\\Pipeline::carry():194}:195}()
#80 /var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(219): Statamic\\Http\\Middleware\\CheckComposerJsonScripts->handle()
#81 /var/www/html/vendor/statamic/cms/src/Http/Middleware/PoweredByHeader.php(18): Illuminate\\Pipeline\\Pipeline->{closure:{closure:Illuminate\\Pipeline\\Pipeline::carry():194}:195}()
#82 /var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(219): Statamic\\Http\\Middleware\\PoweredByHeader->handle()
#83 /var/www/html/vendor/laravel/framework/src/Illuminate/Foundation/Http/Middleware/TransformsRequest.php(21): Illuminate\\Pipeline\\Pipeline->{closure:{closure:Illuminate\\Pipeline\\Pipeline::carry():194}:195}()
#84 /var/www/html/vendor/laravel/framework/src/Illuminate/Foundation/Http/Middleware/ConvertEmptyStringsToNull.php(31): Illuminate\\Foundation\\Http\\Middleware\\TransformsRequest->handle()
#85 /var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(219): Illuminate\\Foundation\\Http\\Middleware\\ConvertEmptyStringsToNull->handle()
#86 /var/www/html/vendor/laravel/framework/src/Illuminate/Foundation/Http/Middleware/TrimStrings.php(47): Illuminate\\Pipeline\\Pipeline->{closure:{closure:Illuminate\\Pipeline\\Pipeline::carry():194}:195}()
#87 /var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(219): Illuminate\\Foundation\\Http\\Middleware\\TrimStrings->handle()
#88 /var/www/html/vendor/laravel/framework/src/Illuminate/Http/Middleware/ValidatePostSize.php(27): Illuminate\\Pipeline\\Pipeline->{closure:{closure:Illuminate\\Pipeline\\Pipeline::carry():194}:195}()
#89 /var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(219): Illuminate\\Http\\Middleware\\ValidatePostSize->handle()
#90 /var/www/html/vendor/laravel/framework/src/Illuminate/Foundation/Http/Middleware/PreventRequestsDuringMaintenance.php(109): Illuminate\\Pipeline\\Pipeline->{closure:{closure:Illuminate\\Pipeline\\Pipeline::carry():194}:195}()
#91 /var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(219): Illuminate\\Foundation\\Http\\Middleware\\PreventRequestsDuringMaintenance->handle()
#92 /var/www/html/vendor/laravel/framework/src/Illuminate/Http/Middleware/HandleCors.php(61): Illuminate\\Pipeline\\Pipeline->{closure:{closure:Illuminate\\Pipeline\\Pipeline::carry():194}:195}()
#93 /var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(219): Illuminate\\Http\\Middleware\\HandleCors->handle()
#94 /var/www/html/vendor/laravel/framework/src/Illuminate/Http/Middleware/TrustProxies.php(58): Illuminate\\Pipeline\\Pipeline->{closure:{closure:Illuminate\\Pipeline\\Pipeline::carry():194}:195}()
#95 /var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(219): Illuminate\\Http\\Middleware\\TrustProxies->handle()
#96 /var/www/html/vendor/laravel/framework/src/Illuminate/Foundation/Http/Middleware/InvokeDeferredCallbacks.php(22): Illuminate\\Pipeline\\Pipeline->{closure:{closure:Illuminate\\Pipeline\\Pipeline::carry():194}:195}()
#97 /var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(219): Illuminate\\Foundation\\Http\\Middleware\\InvokeDeferredCallbacks->handle()
#98 /var/www/html/vendor/laravel/framework/src/Illuminate/Http/Middleware/ValidatePathEncoding.php(28): Illuminate\\Pipeline\\Pipeline->{closure:{closure:Illuminate\\Pipeline\\Pipeline::carry():194}:195}()
#99 /var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(219): Illuminate\\Http\\Middleware\\ValidatePathEncoding->handle()
#100 /var/www/html/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(137): Illuminate\\Pipeline\\Pipeline->{closure:{closure:Illuminate\\Pipeline\\Pipeline::carry():194}:195}()
#101 /var/www/html/vendor/laravel/framework/src/Illuminate/Foundation/Http/Kernel.php(175): Illuminate\\Pipeline\\Pipeline->then()
#102 /var/www/html/vendor/laravel/framework/src/Illuminate/Foundation/Http/Kernel.php(144): Illuminate\\Foundation\\Http\\Kernel->sendRequestThroughRouter()
#103 /var/www/html/vendor/laravel/framework/src/Illuminate/Foundation/Application.php(1220): Illuminate\\Foundation\\Http\\Kernel->handle()
#104 /var/www/html/public/index.php(20): Illuminate\\Foundation\\Application->handleRequest()
#105 {main}
"}

Environment

Environment
Application Name: Statamic
Laravel Version: 13.1.0
PHP Version: 8.3.25
Composer Version: 2.9.3
Environment: local
Debug Mode: ENABLED
URL: bug-test.ddev.site
Maintenance Mode: OFF
Timezone: UTC
Locale: en

Cache
Config: NOT CACHED
Events: NOT CACHED
Routes: NOT CACHED
Views: CACHED

Drivers
Broadcasting: log
Cache: file
Database: mariadb
Logs: stack / single
Mail: smtp
Queue: sync
Session: file

Storage
public/storage: NOT LINKED

Statamic
Addons: 0
Sites: 1
Stache Watcher: Enabled (auto)
Static Caching: Disabled
Version: 6.7.0 PRO

Installation

Fresh statamic/statamic site via CLI

Additional details

Asked AI what the problem was:

Statamic loads columns for the listing based on the first collection specified in the blueprint in order to know what data to query. In this case, it checked the news collection which has a field content configured as a Bard field (which uses Tiptap/ProseMirror under the hood).

When querying the data to populate the link options, Statamic saw that news considers content to be a Bard field. Thus, when it hit an entry in the Blog collection that happened to come first alphabetically (because you started the title with a "1"), it passed the Blog's content array to the Bard::preProcessIndex() method.

However, Blogs's content is a Replicator field containing string data. Because the Bard index preparer expects a specific array schema representing ProseMirror nodes (not raw strings), traversing the string with foreach() in the DOMSerializer threw the crash.

When you changed the title of the Markdown file to start with a letter instead of a number, that file no longer appeared on the first page of results, inadvertently hiding the crash.