Do you have a lot of custom maps? Try temporarily renaming the Maps > Custom folder, and then re-running the client.
Failing that, please follow the guidelines in posting for help with the client.
https://forums.cncnet.org/index.php?topic=6478.0
i already rename that folder like u said but it seems the problem still persist, and im also trying to delete all custom maps and im still encountered the same problem.