Yes, it's 4.1 (in Settings > About > Software Version: 4.10).
I turned it off and on several times. I also tried to do a reset (hold bottom right corner and select to erase all user data). Still it doesn't solve the issue - it tells me maximum number of subs added.
Has anyone actually managed to remove subs - I read elsewhere that once subs are added there's no way to remove them? So maybe I have to buy a new TMC?