# Troubleshooting AWS Client VPN: Client returns a credentials exceed max size error in Client VPN — federated authentication
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**Problem**  
I use federated authentication for my Client VPN endpoint. When clients enter their user name and password in the SAML-based identity provider (IdP) browser window, they get an error that the credentials exceed the maximum supported size.

**Cause**  
The SAML response returned by the IdP exceeds the maximum supported size. For more information, see [Requirements and considerations for SAML-based federated authentication](federated-authentication.md#saml-requirements).

**Solution**  
Try to reduce the number of groups that the user belongs to in the IdP, and try connecting again.