No problems at all for me. No ideas as to what the issue could be... the preferences for AC 16 and 17 are independent, so installing 17 should not have had an affect on 16. The display/graphics drivers and OpenGL drivers are all from Apple as part of OS X.
Lots of other 10.8.4 users here, and you're the first with a situation like this that I recall. Get in touch with US tech support on Monday... but maybe some other folks here will have an idea for you before then.
Just to be sure it isn't a preference / system 'lint'...create a fresh account and log into that and see if 16 OpenGL works there... Also... you do have plenty of free disk space for temporary files / swap files?
Also, is only one of 16 and 17 running when you try this? (Just in case your 4 GB memory is a limitation / issue.) ... and you're displaying everything on the iMac screen, not on an external monitor?
One of the forum moderators
AC 26 USA and earlier • macOS Ventura 13.4, MacBook Pro M2 Max 12CPU/30GPU cores, 32GB