1. Stop "Manage Engine ServiceDesk Plus" service in Services.msc
2. Rename the "Reports" folder under ..\ManageEngine\ServiceDesk.
3. Start "Manage Engine ServiceDesk Plus" service in Services.msc
4. Update the report settings by clicking on "Update" under Reports -> Custom Settings -> Update.
5. Run the particular Report. If the Report is unsuccessful, create Support file immediately under Support/Community tab, send it to us for further analysis.
However my real question is what is causing this, and how do we stop it from happening? Does anyone know why this is happening?