Weird error in logs - TypeError: Cannot read properties of undefined (reading 'then')

Anvil Q&A
1

I just got an emailed error digest from a live app :

Session start time: 2024-09-05 11:26:28
Session Type: Browser Session
Error count: 3
Error messages:
TypeError: Cannot read properties of undefined (reading 'then')
TypeError: Cannot read properties of undefined (reading 'then')
TypeError: Cannot read properties of undefined (reading 'then')

Now, I saw that in another app I was debugging earlier today. It just came on one run and went on the next (no changes made).

Any idea what could cause this? I don’t really know where to start as there’s no other identifying info in the report.

edit - loving the emailed reports, btw.

2

Ok - I don’t think these errors are coming from legitimate users, but how can I find out what they were doing to generate them?

I can’t make it happen using the system as intended.

3

If it’s not legitimate users (ie it’s bots), I could easily believe they have something funky in their JS runtime that’s throwing us off!

If you wanted to investigate further I’d be suggesting a global error handler and introspecting the ExternalError and all sorts of nonsense, but if it’s bots it doesn’t seem worth the faff!

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