Cannot add entries of specific custom note type. (or clone) ("Card template ⁨78⁩ has a problem'")

After updating to Anki 2.1.33 I seem to be unable to add entries with my most frequent note type. This is with addons disabled on Macos.
And I also am unable to clone the note type in order to try to debug it.
It seems to be only 1 note type which misbehaves as I can add or clone other note types.

I believe adding worked for this note type before upgrading.
(And the help suggestions in the message did not help)

Result for ‘Add’:

    Error
    An error occurred. Please use Tools > Check Database to see if that fixes the problem.
    If problems persist, please report the problem on our support site. Please copy and paste the information below into your report.
    Anki 2.1.33 (3f403040) Python 3.8.0 Qt 5.14.2 PyQt 5.14.2
    Platform: Mac 10.15.6
    Flags: frz=True ao=False sv=1
    Add-ons, last update check: 2020-09-12 10:34:05

    Caught exception:
    Traceback (most recent call last):
      File "aqt/webview.py", line 493, in handler
      File "aqt/editor.py", line 481, in <lambda>
      File "aqt/addcards.py", line 190, in _addCards
      File "aqt/editor.py", line 593, in saveAddModeVars
      File "anki/models.py", line 87, in save
      File "anki/models.py", line 231, in update
      File "anki/rsbackend_gen.py", line 414, in add_or_update_notetype
      File "anki/rsbackend.py", line 265, in _run_command
    anki.rsbackend.TemplateError: Card template ⁨78⁩ has a problem.

Result for new note type with cloning of the problematic note type:

Error
An error occurred. Please use Tools > Check Database to see if that fixes the problem.
If problems persist, please report the problem on our support site. Please copy and paste the information below into your report.
Anki 2.1.33 (3f403040) Python 3.8.0 Qt 5.14.2 PyQt 5.14.2
Platform: Mac 10.15.6
Flags: frz=True ao=False sv=1
Add-ons, last update check: 2020-09-12 10:34:05

Caught exception:
Traceback (most recent call last):
  File "aqt/models.py", line 230, in accept
  File "anki/models.py", line 265, in copy
  File "anki/models.py", line 220, in add
  File "anki/models.py", line 87, in save
  File "anki/models.py", line 231, in update
  File "anki/rsbackend_gen.py", line 414, in add_or_update_notetype
  File "anki/rsbackend.py", line 265, in _run_command
anki.rsbackend.TemplateError: Card template ⁨78⁩ has a problem.

Search for problems in Card template ⁨78⁩ as the error message suggests.
You can post the template content here so we can help you.

1 Like

Thanks,
problem solved.

It was a name mismatch between opening and closing html tags.
Not sure why this became a problem now, as this bug must have been introduced last year.
(And I add new entries more often then once a week)