Unable to convert trigger to CosmosDBTrigger.

[alohaninja]

Investigative information

Unable to use .NET for new cosmos triggers (Exception binding parameter 'documents'). Modifying existing ones is also breaking with this same error when updating assemblies. Javscript cosmos triggers are working just fine.

First reported on SO about 9 hours ago...

Repro steps

Create new cosmos db c# trigger from the portal.

Expected behavior

Cosmos trigger fires as expected and bindings work without issue

Actual behavior

Exception while executing function: Functions.onCollectionChanged 
Microsoft.Azure.WebJobs.Host.FunctionInvocationException : Exception while executing function: Functions.onCollectionChanged ---> System.InvalidOperationException : Exception binding parameter 'documents' ---> System.InvalidOperationException : Unable to convert trigger to CosmosDBTrigger.
   at Microsoft.Azure.WebJobs.Extensions.DocumentDB.CosmosDBTriggerBinding.BindAsync(Object value,ValueBindingContext context)
   at async Microsoft.Azure.WebJobs.Host.Triggers.TriggeredFunctionBinding`1.BindCoreAsync[TTriggerValue](ValueBindingContext context,Object value,IDictionary`2 parameters) 
   End of inner exception
   at Microsoft.Azure.WebJobs.Host.Executors.DelayedException.Throw()
   at async Microsoft.Azure.WebJobs.Host.Executors.FunctionExecutor.ExecuteWithWatchersAsync(IFunctionInstance instance,ParameterHelper parameterHelper,TraceWriter traceWriter,CancellationTokenSource functionCancellationTokenSource)
   at async Microsoft.Azure.WebJobs.Host.Executors.FunctionExecutor.ExecuteWithLoggingAsync(??)
   at async Microsoft.Azure.WebJobs.Host.Executors.FunctionExecutor.ExecuteWithLoggingAsync(??) 
   End of inner exception

[alohaninja]

You cannot trigger (aka RUN) a new cosmos trigger from the portal directly or you receive this error. You just need to create OR update a document in the monitored collection and the trigger will fire as expected.

[psfinaki]

@alohaninja Confirmed, works. Thank you! (just wanted to say thanks somewhere, I am the guy who asked the SO question)

[jimwilliam]

i'm not running a trigger function from the portal but getting it when items arrive and the trigger reading off of the change feed fires. I've not seen that before.