OK, so now we all know that the definitive' answer' (or not!) is that Adobe CS6 'can be' problematical in certain circumstances in operation under El Capitan.
The most common reason I've seen for those having problems with CS6 and older CS releases under El Capitan is when users upgrade the OS over an older version. What then fixes the Adobe apps (more often than not), is to uninstall the Adobe software and reinstall it.
I am in the same situation as many impoverished designers in that I just cannot afford to pay a subscription for CC and quite frankly am annoyed that we are being forced to pay up or lose out.
It annoys me, too, but I need to keep current with my clients so there's no issue opening files in either direction. Thankfully, what I make on the work easily covers the monthly subscription fee. But if it weren't for the work, there's no way I'd continue on the CC trail at $50 a month. I've got the CS6 Master Collection and a separate Photoshop CS6 package. I'll go back to those come the day I close the business down. Or, maybe by then, Adobe will go back to perpetual license as at least an option.
Before the CC stuff happened, Adobe sent out a lengthy questionnaire to all customers who had registered their software. Lots of the same questions asked in different ways, but boiled down to;
1) Would you rather continue a perpetual license, or would you prefer a monthly subscription service?
2) What would you think would be a fair cost for this service (radio button choices of various amounts to click)?
You could see where that was going. There was no doubt in my mind a subscription service was coming regardless of how many people said NO!!!!. More than anything else, Adobe wanted to know how much they could charge a month without causing an exodus.