I just encountered this bug. My masonries were working fine and I built an Expert Mason improvement and suddenly my towers won't convert to stone anymore.
Doing some testing, I can now confirm that it appears to be caused by the Spyglass Overlook. I built the exact same structures at another village without the spyglass and everything upgraded just fine.
I just encountered this bug. My masonries were working fine and I built an Expert Mason improvement and suddenly my towers won't convert to stone anymore.
Doing some testing, I can now confirm that it appears to be caused by the Spyglass Overlook. I built the exact same structures at another village without the spyglass and everything upgraded just fine.