Ever since I installed Cubase trial, I began to have this problem. I uninstalled Cubase, I even uninstalled and reinstalled Sequel but no luck.
When I start Sequel, I get this dialog showing the license error for organs (see attached). I hit ok and Sequel start just fine. Later as I pick instruments (not sure which) this dialog pops up about no valid license (see attached). Retry keeps showing the same dialog and cancel causes Sequel to crash. Crash dump is also a attached.