The problem *seems* to be related to older custom workspace .xml files. It took uninstalling and reinstalling twice but saw the change after the first reinstall. The Layers panel worked correctly upon initial launch but switching to custom workspace (that had not been removed from the preferences even though I indicated that they should be removed during the uninstall routine) caused a repeat of the problem. After the second reinstall, I ensured the Layers panel was working correctly and saved the workspace as presented as a custom workspace. I then manually removed the old workspace .xml files (which had reappeared after the reinstall though weren’t there after the uninstall–yeah, I’m puzzled). Finally, I created a custom workspace to my liking and tested.
I should note a couple of other things. Trying to resolve the problem, I did a Java update which did nothing. The unaffected iMac has exactly the same video card but no custom InDesign workspaces. The reinstalls took care of a display issue (type cut off) in InDesign’s Preferences, specifically the Interface section. I doubt that fix can be attributed to the .xml file, but the Java update didn’t fix it either.
I still need to take a look at the second problem iMac….
.
