What computer operating system is involved? Have you updated 12 to 12.1 yet using an opened project's Help Menu/Updates?
Many of these CAHeadless error messages point to the Elements Organizer and AutoAnalzyer.
Please explore each of the following
a. Elements Organizer 12/12.1. Edit Menu/Preferences/Media Analysis and turning off all the options under that category.
b. Elements Organizer 12/12.1. File Menu/Manage Catalogs/Catalog Manager. Repair and Optimize present catalog. If that does not help, then create a new catalog.
c. Delete the Elements Organizer 12/12.1 setting file named psa.prf
Local Disk C
and in the Organizer Folder is the psa.prf file that you delete or disable by renaming it to psa.prfOLD.
Please let us know if any of the above worked for you.