On Language Learning Stack Exchange, someone reported an issue that came up after the latest update. One of their older cards triggered an error message that said, “Error message: Card template 1 in notetype ‘2. Mnemocis (For Radicals)’ has a problem. See the preview for more information.”
The full question is on languagelearning.stackexchange… (unfortunately, I can’t include a link, not even the domain name, which deminishes the usefulness of this post).
I don’t know whether this question will be answered here or on Language Learning Stack Exchange, but I would like to use this opportunity to say that we regularly get questions about Anki on that Stack Exchange site. A number of them have also been answered, so people from this forum may also be interested in the questions over there.