Earlier, Bitcoin Cash (BCH) completed its scheduled hard fork upgrade on November 15. However, its first block is considered invalid by its older client version, Bitcoin ABC 0.19.0. Today, SBI VC Trade said on Twitter that due to certain issues, users cannot "receive and send" the BCH through the Cool X wallet. It also notifies the user of the fix once it is found. Hard forks make simple changes to the consistent protocol. However, what worries the community is that the "difficulty adjustment algorithm" has not been resolved.