This bug preventing Anki to open has been a problem for several years and is caused by addon Anki Zoom. I already fixed it but there is nothing I can do about it because the original author is no longer active.
This bug is caused by an error in the loop. The user cannot operate Anki because a lot of dialogs are displayed.
I think a workaround is to make the dialogs non-modal and limit the number of error dialogs. I have developed an add-on for this purpose, limit the number of dialogs to 3 and any more than that will show a tooltip:
But as far as I know such an error is rare, plus there are some other add-ons bugs causing prevent Anki working. So I don’t know if it is worth embedding a workaround in Anki for desktop. (Edit: If non-modal the process will continue to occur so other problems may occur.)
So it seems to me that just removing Zoom’s add-on page by the official Anki would be enough. Or force a configuration change to make it unusable in versions of Anki where users do not support this add-on. (The last version that this add-on works was 2.1.49, and it does not work from 2.1.50.)
This add-on is recommended for use by other add-ons, so perhaps users are downloading it without reading the add-on ratings. Or it happens when a user with old Anki updates Anki. So if the user cannot update and download, this problem will not occur.