That’s insufficient information to provide any meaningful assistance. You should provide additional information about technologies, Auth0 configuration being used, possible libraries/SDK’s, etc.
With the information provided (unless you’re lucky to have someone that already experienced the same exact error reading this) it’s unlikely for you to receive definitive answer. Having said that I can still provide a GTFY approach so for that error, we have:
However, if Google has it right and the source of the error is IdentityServer you’ll likely have better support if you go straight to the source or use a more general Q&A platform like StackOverflow.