Resources and production Issue

My own production sources (food, wood, stone, Iron, and Gold) stopped accumulating resources after I started upgrading production in the technology research. When I click one, the 'receive' button is colored gray and it is unclickable. I tried to clear the cache and it worked temporarily, but when I opened the game again the issue is still there.

Is there anyone who had experienced the same thing? If so, how did you fix it?