building latest development helmet bubble does not come out

What level are you? There is a sort of cap that wont allow more than x buildings to be fully upgraded on each level.

16 lvl

16 lvl

16 lvl i am

İt is normal?

Yeah, they added that limit a while back, to "discourage" level camping. If you want, try upgrading other buildings until you level up, and then try to upgrade those.

Thank you very much