Sometimes I get this error message when I try to post a comment, then I just cant comment under that post at all. On other posts it does work like it should. I have checked the language settings and they are set proberly. Is this a Voyager-problem or a Lemmy-problem?
I got this and had to log into my home instance and under settings in my profile, there is a list of languages. I had to hold ctrl to select "undetermined" and "English". After I saved that it seemed to fix things here.
The "undetermined" language you want to keep, otherwise it will filter out many posts.
This doesn't resolve the issue of the OP. I'm addition to having a language in your user profile, the desktop version of Lemmy also let's you select a language for each comment you make (which I suppose makes sense if you are bilingual).
Your profile language selects what languages you view, but the comment language selects what language you are posting in. There is zero way to select a default language when posting for some reason. Also for some reason, sometimes when the OP specifically selects a language, it will not let you comment if your comment language is undefined. But, as I said earlier, your comment language will always be undefined unless you explicitly change it for each comment.
This is a Lemmy-side bug. The only way for Voyager to resolve it is to add a functionality of choosing your comment language in your posts.