Something went wrong with repetition algorithm: for certain items number of days until the next review is quite impossible. Bug affects community courses as well as official ones (first screen is official Chinese). There could be other corrupted items with much less number of days, looking normal at the first sight.
It could just be a presentation bug in the screen, but Memrise engineering might have more info. I opened up five different levels, each in separate classes, and they all looked fine with the timestamps.
Hard to tell if I saw them after reporting, one too many things to remember, but just now I’ve checked Chinese course - this item is for review in 1179179 days, so timer is working alright (211 day passed according to it). No, I haven’t restarted any of those courses.
Thanks for reporting this. I can reproduce the issue.
I’ve raised a ticket with the relevant team so they can have a look asap (internal tracking code QA-720). Unfortunately I have no timeframe for the fix but I’ll make sure to update the thread once I have any news.