I am wondering if I update my system software to Sierra will it affect my Illustrator, Photoshop, etc programs. I have CS6 versions of Adobe and don't want to have to update those programs.

Per Adobe's website, CS6 does not work with Sierra or above.

Regrettably, I updated to High Sierra on both my Macbook Pro and iMac (both purchcased early last year). In both cases, the separately-licensed PhotoShop I have installed on each system has a major glitch. When opening "File Info" to program metadata (keywords, copyright info, etc.) the window turns blank and the application freezes — leaving Force Quit as the only option for escape. From now on, I am resolved to return to my older macs (which I still have and are functioning well) for my professional daily work and use the new Macs and their continually updated systems for secure Internet connection and communication only. I have the same problem with PowerPoint crashing on my newer Macs. I regularly travel giving public talks with Slides. So, I have to carry both the old and new Macbook Pro laptops with me. Rather inconvenient, but at this point there is no other choice when using my Apple products, if I wish to both maintain the latest in secure Internet connectivity and perform my daily professional tasks.

the framework in Sierra is pretty much the same as High Sierra (HS) so if you got CS5 to work in Sierra it should work in HS. All that aside Apple has said HS is the last 32/64 bit OS for Mac and most if not all of CS5E is 32 bit so proceed at your discretion.

At this time if you download HS from the Apple Store the patch is already included.

Perhaps the best course of action is to reflect on just how you use the older, non-subscription Adobe products, the inputs and output files, and what current third-party software can achieve the same without exorbitant purchase cost, or subscription model.

Affinity Designer, Affinity Photo (each $50USD), and Pixelmator Pro ($60) all have fully functional trialware from the respective vendor sites, are available in the Mac App Store, and may actually allow you to achieve your goals without remaining an Adobe hostage. Don't let these prices deceive you, as they are full of pro features.

I own Affinity Designer and Photo — but receive no compensation, or special benefit from their recommendation. I don't own Pixelmator, with the same proviso.

I'm sure these products are viable alternatives to Photoshop and fulfill many image manipulation needs. But, the one issue that drew me to comment on this thread was that after upgrading to High Sierra, PhotoShop would freeze upon accessing FILE INFO. This useful tool allows me to enter the title, description, keywords, instructions, copyright notice and other pertinent file metadata. It appears that AFFINITY PHOTO has no such capability. The $50 price tag is attractive, but, I'd gladly pay three to four times that amount to get the metadata entry capability featured in PhotoShop. My advice is to avoid upgrading to High Sierra. I for one will revert to plain old Sierra OS.

Since only High Sierra is only available now that sort of make your question somewhat pointless.

El Capitan is still available at How to download OS X El Capitan - Apple Support
From what I gather from discussions, CS4 will still work on El Capitan, so CS5 should work.

Ignore this post.

El Capitan is still available.

Regarding Affinity Photo and Pixelmator Pro... will these products open older Adobe Photoshop and Illustrator files that we already have?

Only available for macs that cannot upgrade to Sierra and High Sierra. Or if you had downloaded it previously.

Ok Ok lets just slow down there. Sierra can still be downloaded, if you were interested.

How to download macOS Sierra - Apple Support

But as you are really wanting High Sierra, fine.

Please go to this website, https://roaringapps.com/ this will give you information on how your third party apps will function in different macOS's. It is a guide and not definitive. You can enter the site from the left hand side by pressing View macOS apps. When the table loads up go to the search field and enter Adobe CS6 it will then show you a list of the suites apps and how they will function in High Sierra etc. Or on the right hand side of the introduction page you can elect to download the app which once downloaded and run will search through your mac and then list the apps you run and show a table of their status in High Sierra etc.

Adobe says the apps are not compatible with High Sierra for obvious commercial reasons.

I m running Photoshop CS6 Extended and it is fine, the only thing that I have noticed is that when in Camera Raw when your cursor hovers over an item the tool tip appears but does not disappear, so the screen can get a little cluttered. You can switch off the Tool tips in Photoshop>Preferences>Interface. This problem only occurs in Camera Raw not in the main Photoshop dialogue.

Are you running inSierra or High Sierra. I just bought new iMac with Sierra and my CS5 extended is working on Sierra. Am afraid to upgrade to High Sierra and lose what I have. Would only like to upgrade because of security issue With Mac and I was told they have a new patch for High Sierra.