The issue of Discourse-Assign having poor support for non-English characters leading to a 500 Error seems to be a common topic, so here we will only discuss a problem that arises in a rather embarrassing combination of circumstances:
Discourse has a useful auxiliary feature—it replaces strings on the page with localized names each time it runs Jobs::EnsureDbConsistency. This should be praised as an absolutely user-friendly feature, but in this case, it can do more harm than good: Taking Simplified Chinese as an example, we first adjust the default language to this non-English language, then run Jobs::EnsureDbConsistency. Subsequently, it will change the names of Automatic groups, and then when users open the Assigned page for that group, it triggers a 500 Error.
In summary, to use Discourse-Assign normally in these languages, you need to first set the default language to English and run Jobs::EnsureDbConsistency so that the group names are in English, and then adjust the default language back to the target language to make the Full Name become Chinese.
However, since Jobs::EnsureDbConsistency runs periodically under normal circumstances, the next time it is triggered, the names of Automatic groups will revert to the target language, again causing the Assigned page to trigger a 500 Error. 