Spectrum that is configured to use EEM, users are not able to log into either the Spectrum OneClick web page or the Spectrum OneClick Console. They receive an "HTTP error code 500" when trying to log in. If the Authentication Logging is enabled in the OneClick Single Sign-On Configuration web page, the debug output will show that these users are authenticating with EEM correctly but still unable to login.
The root cause of the problem is the information received from the EEM server for some users is too large for the http header.
The solution is to increase the http header size in OneClick by doing the following on the OneClick server: