On some machines, quickFilters is not loading at startup

[RealRaven2000]

On some installations quickFilters doesn't load any UI on startup, and needs to be reloaded from Add-ons Manager to work.

A similar problem was found in QuickFolders following the execution of accounts code on startup, with a similar error message as thisL:

jar:file:///C:/Users/Stephen/AppData/Roaming/Thunderbird/Profiles/tolc144y.default/extensions/quickfolders@curious.be.xpi!/chrome/content/api/
ex_accounts/implementation.js :: traverseSubfolders :: line 142"  data: no] 
implementation.js:142:25
Uncaught (in promise) Error: An unexpected error occurred undefined

[RealRaven2000]

The following test version should guard against the problem in Thunderbird startup until the bug is fixed in Thunderbird:

quickFilters-wx-5.3pre74.zip

To install, download the zip file and then drag it into Thunderbird Add-ons Manager.

It will log in the Error console which of the accounts gives trouble when trying to access it with the accounts API.
Either:
traverseSubfolders failed: account ex
convertAccount failed: account ex

(Clicking on account will expand the object and show which account gave problems on startup)

[RealRaven2000]

Fixed in 5.3, released on 04/04/2021