After Upgrading Spectrum if you are getting this error while trying to access OneClick with the Spectrum install user, try restarting the Tomcat web server service. We have seen in a few instances where simply restarting Tomcat service will clear this error.
If a Tomcat restart does not solve the issue, then we would suggest investigating further, and opening a support ticket if necessary.
For instance, if you are still seeing this error after a Tomcat restart, check the Tomcat Log for any "java.lang.NullPointerException" messages. If you find them, please reference TEC 561657 and try to clear DuplicateLlist(0x11cd5) attribute on the Spectrum User model: https://support.ca.com/us/knowledge-base-articles.tec561657.html