Anki Syncing keeps failing

Everytime I try to open the anki app on my desktop and it starts to automatically sync or when I press sync, I get the following message:

Syncing failed:
Traceback (most recent call last):
File “aqt/”, line 376, in _sync
File “aqt/”, line 356, in _abortingSync
File “anki/”, line 114, in sync
File “anki/”, line 611, in applyChunk
File “anki/”, line 624, in _run
File “anki/”, line 559, in req
File “anki/”, line 498, in assertOk
Exception: Unknown response code: 400

Not sure what to do about this. Thanks in advance!

Try the standard list of troubleshooting steps, then report back:
When problems occur - Frequently Asked Questions (

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After updating to the latest Anki, please use Tools>Check Database, then force a one-way sync to AnkiWeb in the preferences screen - that will likely resolve whatever issue you’re having.