HELP

I have 2 ID and myself with Articulate Studio 13 installed on our company issued computers. Recently, there is an issue with Engage.  In all previously created courses, the interactions are not appearing when you click on the Engage button in the ribbon.  We tried dozens of courses.  We have reinstalled and repaired multiple times to no avail. If we choose to add an existing interaction, it comes in as a BLANK slide with a name of Slide 0. Regardless of the file or interaction name.  We are dumbfounded.  PLEASE help.