It sounds like the Fastvue Reporter service may be struggling. Can you try stopping/starting the Fastvue Reporter service (in services.msc).
Then go to *Settings | Reports | Existing Reports* and delete any 'failed' or 'pending' reports.
Make sure your server meets our recommended requirements at https://www.fastvue.co/sophos/getting-started
Then try running your reports again.
If you're still having issues, please enable verbose logging, reproduce the issue, and then send us the Dashboard.log file? The log should include some diagnostic information to help us troubleshoot this for you.
To do this: 1. Go to *Settings | Diagnostic* and note the location of the *Dashboard.log* file. 2. Stop the Fastvue Reporter service (services.msc), then *delete the Dashboard.log file*. 3. Restart the Fastvue Reporter for SonicWall service, then go to *Settings | Diagnostic* and set the logging level to 'Verbose' (slider in the middle). 4. Delete and regenerate your report(s) to reproduce the issue 5. Zip and upload the *Dashboard.log* file to http://www.fastvue.co/upload