Hi! I have been using Photoshop on my iMac for several years and now all of a sudden it says that it is not compatable and I need to update my software. I am currently running Yosemite10.10.5 and my computer says that there are no updates available. I have tried to figure out how to install an older version on Photoshop but haven't had luck with that either! Any suggestions? My work depends on photoshop!
In short, you should be able to upgrade the iMac to macOS 10.13 High Sierra, and that would let you upgrade Photoshop to last year’s version 2020 (v21). And that is as far as that 10-year-old iMac will go.
How to understand this:
Apple tends to support Macs for about seven years. After that, they start to drop support for them in macOS upgrades. That is why your iMac can’t be upgraded past macOS 10.13.
Adobe, as said above, provides only the current and previous versions of its applications.
Your iMac is old enough that it’s unable to be upgraded to a version of macOS that’s supported by the latest version of Photoshop.
One final note: Although you shoudl be able to install Photoshop 2020 if the iMac is upgraded to macOS 10.13, if a new version of Photoshop is released this fall as has happened the last few years, Photoshop 2020 will be dropped and then no version will be available to be installed on that iMac.
After Adobe stops allowing installation of Photoshop 2020, its installer might be available from prodesigntools.com.