SSD appears in start up disk preference but won't boot

[whapweasel]

I have a 2017 27’ Imac with a 500gb SSD formatted in APFS , OS High Sierra 10.13.3


With my previous iMac (graphic card failed) I used an external 250gb SanDisk SSD formatted with Mac OS extended journal.

This SSD was bootable using OS X Yosemite.

When I connect this external SSD to my new iMac it appears in the start up disks preference but when I try to start up from the external SSD the screen goes dark and the computer freezes.

The reason I want to start up from this external SSD is because it has a version of Adobe Photoshop which is not compatible with High Sierra and Photoshop is very expensive.

Could this be a formatting issue and /or a High Sierra Issue ?

Thank you for any assistance.

 

[Weaselboy]

This SSD was bootable using OS X Yosemite.

This is your problem. A 2017 iMac will not run on Yosemite.

 

[MarkC426]

Which version of Photoshop are you using?
I have CS5 Extended running in Sierra.

 

[whapweasel]

Which version of Photoshop are you using?
I have CS5 Extended running in Sierra.

It was CS4

 

[MarkC426]

Roaring apps seems to say it works!
https://roaringapps.com/app/adobe-photoshop-cs4

 

[BLUEDOG314]

Might be able to fire up migration assistant and have it pull over the app for you. Haven't done migration assistant after initial setup in some time but I think it'll work. You may have to end up with an extra random user account though.