I tried opening the report designer and it says it’s inactive. I checked the module configuration in the gateway and it says it’s activated and running. Version 3.8.0. Ignition version 7.8.
nevermind. You have to right click and select new report. 
I’ve ran into a similar issue, where the report is stuck at ‘Loading…’, and the key browser says ‘Report designer inactive.’
The fix for me, was fixing a long-running query, that was queuing 1000000’s of entries from the alarm journal…
Fixing the data / code let the report design tab open.