Hi @Shubham_Raikwar ! Thanks for reporting this.
Previously we have other users reported the same error last week, and our team fixed it around the day that you created this post. Would you please confirm if you are still having this issue right now? If yes, kindly provide more details to us.
https://builder.metamask.io/t/auth-verify-fails-signatures-0-must-be-500-characters-account-abstraction