Anki desktop creates merge conflict even with no changes since last sync

[lex1]

Anki desktop seems to be creating incompatibilities with Ankimobile such that I cannot sync between my phone and my desktop. Desktop creates these conflicts even if I force pull from AnkiWeb, make no changes to my collection, and them immediately attempt to push. Here’s what happens:

1. I do some reviews on Mobile and do a sync;
2. I go to pull from Desktop, get a merge conflict, choose ‘download from AnkiWeb’. Now the reviews I just did on Mobile are reflected on Desktop.
3. I immediately click ‘sync’ again on Desktop, get a merge conflict.

Desktop details:

Version 2.1.23 (de9543ff)
Python 3.8.0 Qt 5.13.1 PyQt 5.14.1

Any ideas?

I remember something like this happened following an update a few months ago and the problem involved errant tags or card types or something, but I’m unable to find the solution I used at that time.

[ferophila]

The first thing I‘d do is to update this very old (3 years!) Anki version.

[lex1]

Wow yes, that did it. Thanks!