I age up to Classical Era and suddenly my unit production is disabled -- it says that there are no spawn points even though the city is empty. Can be fixed by building garrison but it seems like an obvious bug.
Step by step of the bug
Step 1
Age up to Classical Era
Step 2
Unit Creation Disabled Due to Lack of Available Spawn Point
I age up to Classical Era and suddenly my unit production is disabled -- it says that there are no spawn points even though the city is empty. Can be fixed by building garrison but it seems like an obvious bug.