. . . I have been working with Macs since the 1980s and the El Capitan upgrade has given me more headaches than I ever remember with any system.
I agree. Even after several updates, I’m having an unusual number of crashes/hangs. It is getting better, though.
I upgraded to El Capitan before upgrading to QTR 2.7.7, and wound up having to spend several hours with permission issues. Essentially I was unable to install any new profiles with SIP enabled. I wound up having to reboot the OS in Recovery mode to disable SIV in order to change the permissions.
The release notes for 2.7.7 are about El Capitan compatibility:
This is a Mac OSX only release specifically for OSX El Capitan compatibility.El Capitan prohibits installations in an area that was used by QTR so this update movesthose files to a permitted area.It's recommended that you update QTR to 2.7.7 before updating your OSX to El Capitan.This cleans out the old locations while access is still permitted. If you don't QTR stillwill work just fine but if you Add Printer in System Preferences it will appear that 2.7.6is still installed -- in fact this will point to new code but the 2.7.6 may be confusing.
. . . decided to upgrade to 2.7.7. OK, I am still trying to figure out how to open the .dmg file in El Capitan.
If El Capitan won’t let you open the .dmg file, go to System-Preferences / Security-and-Privacy, and look at the bottom half of the box. If you just failed with a .dmg file, there will be a message explaining that it was not from the right sort of developer
and giving you the option to “Open Anyway”. Click on that and the blocked .dmg file will open.
On a “clean” installation of El Capitan, QTR 2.7.7 installed without a hiccup, as did installing support for the Epson 3880 UC.
Myron