To resolve conflicting Optimizer Files:
-Save your work on all seats of Mozaik & close Mozaik and the Optimizer on them
-Go to C:/Mozaik/Jobs (or the Jobs folder in your shared file location)
-Open the Job you're working on
-Delete all .OPT files
Once this is done, you should be able to open the Job in Mozaik & re-Optimize.