You are logged in to the Notification Server console with an account other than the Symantec Administrator and are loading a report that you've previously used successfully. The report contains a filter parameter selector as a drop-down menu but, when clicking the selector, no drop-down list appears and you are unable to run the report without one. 

The report will attempt to load the last filter that was selected by the logged in user. In this case that filter has been deleted by an administrator. This will cause the filter menu parameter to lock-out and no other ones can be selected, even if the user has rights to see other filters. 

A permanent fix is available ITMS 8.1 RU4 (Release Update). Upgrade using DOC10690

Workarounds:

 As a Symantec Administrator: 

1. Instead of deleting the filter, remove the permissions to the user groups required by right-clicking, selecting properties, security and removing read access for the required groups. This will prevent the filter displaying as a selectable option, but will not prevent the drop-down list itself from displaying other available filters to the affected user/group. 
2. To remediate already affected reports:
   1. Edit the report
   2. In the Report Parameters tab, select the filter list parameter, edit it and make a note or screen shot of the settings it uses
   3. Delete the filter list parameter then Save the report
   4. Add the parameter back with the same settings then Save
   5. The affected users will now see the option to select the filter list once again
3. If step 2 does not resolve the issue review TECH248018