I don't think thats a bug, If you notice you can now upgrade equipment for your mercenary troops, and you can no longer get troops from villages. (As far as I know.)
its confirmed as a bug that you cant hire npcs besides merc's and that you cant upgrade them....but its likes the dev's dont care, they dont respond at all. wich is sad
I disagree with this specific solution for this issue.
Devs just lack planning attitude, and don`t release every little fix, which (by the way) overwrites like half of the games DB files.
Instead, they should plan releases, and CH should do the same. I don`t think that one update per week is too much to ask...
We can't plan for something we don't expect to happen.
So we have a plan, if there is a lot of updates then we will wait until the updates stop within a week or so then do a trainer.
No point updating several trainers that will ultimately never get used again.