You may receive intermittent errors from the server that is running Microsoft Forefront Unified Access Gateway (UAG) 2010. These errors usually occur during the logon process, and you may receive an HTTP 500 error code. However, you may receive an HTTP 400 error code or Forefront UAG error code 152. This problem is frequently triggered by heavy load conditions on the Forefront UAG server.
If you perform tracing in Forefront UAG, encryption or decryption errors may occur that resemble the following in the trace:
[whlsecurityutilities CSSOHelpers::Decrypt SSOHelpers.cpp@524] ERROR:CryptoKey::Decrypt() BCryptDecrypt2 Status[-1073741762]
[whlsecurityutilities CSignatureHandler::RemoveSignature SignatureHandler.cpp@233] ERROR:CSSOHelpers::Decrypt failed