Looking at the basic fact about the limit of bitcoin according to the protocol for the bitcoin network,it was design with a limit of 21 million coin.
My question now is are cryptocurrency miners be unable to generate new bitcoin after it reach the 21 million coin limit?
Since there are over 19.15 million bitcoins in circulation if am not mistaken.
You are correction that the maximum limit of Bitcoin can be mined is 21 Million and miners won't be able to create new Bitcoin once this limit is reached as well as they won't be no longer receiving any block reward, but they will continue receiving fee for verifying the transactions even after all Bitcoins are mined. The limit of 21 Million is set in the code which can only be changed with a hard fork, which would require agreement of the community.