It seems that after the GUI error was corrected, the last of update to Mystic somehow removed the QC/Automation of the Raster Control.
- Empty project
- Instrument Track for Mystic
- Right-click Raster Control
- No QC/Automation available for the control.
Raster can not be assigned to QC and can not be automated. Checked both generic GUI and the regular instrument GUI. 
All other controls in the instrument can be assigned to QC slots for automation. Again, this seems to have happened with the last update to the instrument after the previous GUI issue was corrected.