In addition to my post: I looked at the Adobe crash log and found two errors:
Application Specific Information:
terminating with uncaught exception of type std::runtime_error: CMutexObj::CMutexObj init lock error - : No such file or directory
Logical CPU: 0
Error Code: 0xffffffda
Trap Number: 132
I don't understand these.
OK, in answer to my own query I found this: "A mutually exclusive (or mutex) lock acts as a protective barrier around a resource. A mutex is a type of semaphore that grants access to only one thread at a time. If a mutex is in use and another thread tries to acquire it, that thread blocks until the mutex is released by its original holder. If multiple threads compete for the same mutex, only one at a time is allowed access to it."
But I still understand what is going on.
CS4, and for that matter, all perpetual CS versions are unsupported under El Capitan. The older the version, the less likely you'll get it to run.
I'm sorry, but you're completely on your own here.
Thx Bob...But's strange: my old iMac was also running Capitan and there was no problem – although the actual installations were made under a much earlier version of the OS ... so the answer, by implication is: install under and old system and then update (not very practical). That, in turn, suggests there is an easy answer to this out there somewhere!
Also, I run Indesign 5.5 on my newish Macbook laptop – no problem there ... and I'm sure I purchased it with El Capitan (not sure; it was about two to three months ago).
Bob, I think I'll download Yosemite and install it on a drive, try and boot off that and install Adobe again, then switch back to Capitan. Sound like it's worth a try....?
Not to me, but don’t let that stop you.
You never know.