In late December we reached out to Deltek for support on an issue we were having with Costpoint timesheet import and expense preprocessor applications. They confirmed that this issue was due to feature enhancements in Costpoint 8.2.6.
As a temporary measure they have disabled the 'Show Period of Performance Warning Message' check box in the Configure Project Settings application to prevent further performance degradation. Their permanent fix will come with their January maintenance release, where they plan to roll back the changes that cause the initial issue. They have also stated that after the January maintenance, users will have the option to turn on the warning message again if preferable.
If you have experienced this Costpoint 8.2.6 timesheet and expense issue and would like more insight or workaround support please reach out to us for assistance. If this issue persists past the January maintenance release, please let us know and we will work with Deltek to resolve the issue.