Arelith

After leveling up my character is unable to rest.

I click rest and it cancels instantly. Currently, he is now at -18.2% for resting

Added screenshot as without resting I cannot play the character. Lesser Restoration scrolls add up.

What race is the character?
Did you try resting indoors?

I don't believe my disabling of the sleeper code has gone live yet.

And you were not affected by that new spell / curse that dont allow you to sleep? Nightmare was it?

Update: Used removed curse and restoration without any effect. Interestingly enough I turned in the writ I had (Harborage in Skal) and suddenly I could rest again.

If this is since last reset, that's why. The Sequencer stave update also had the rest fix.