Hitting into this after PDOException (There is already an active transaction)

I am running Appwrite 1.3.7 and I encountered PDOException after I tried to delete a few documents with relationships. I decided to restart the Appwrite server and now I'm encountering an "unknown" error:

appwrite | [Error] Timestamp: 2023-10-17T13:07:53+00:00
appwrite | [Error] Type: Utopia\Exception
appwrite | [Error] Message: Not Found
appwrite | [Error] File: /usr/src/code/vendor/utopia-php/framework/src/App.php
appwrite | [Error] Line: 803

To be honest, things were really quite OK until we ran into this problem. Not sure what to try.

I don't normally scream for help but this is a case whereby a few weeks' worth of effort would be ruined because we couldn't put up anything for a demo with invited key stakeholders tomorrow.

I have seen this on 1.4.5 as well. I had a collection, say A that had relationship with collection B .
If I'd perform a delete, the server would freeze and the logs would display the same error as shared above. I had to simply remove the relationship by deleting the whole collection B. A restart later fixed it for me.

Afaik relationships are still marked as experimental so I'd suggest that if you have a lot of data in relationships, use an identifier based logic to link a document or start over.

Thanks for the reply. You are saying that if I delete a doc in collection A and if A has a relationship with collection B then I need to "burn down" the whole collection B?
I had the impression that I'd just kill collection A and recreate that collection