Mac won't boot on certain computer

[XboxMySocks]

Hey guys, was previously running this SSD through a USB successfully on an older computer, but now when I go to try and use it, it does this on the Mac I own (when used internally)

http://www.atrashids.com/v1/wp-content/uploads/2011/03/032411_0959_TipsGuideso2.jpg

Any ideas? Help? Thanks.

 

[Weaselboy]

What OS X version is on the SSD, and what year and model Mac are you trying to run it on? It could be the OS X version on the SSD is too old to run on that Mac.

 

[XboxMySocks]

What OS X version is on the SSD, and what year and model Mac are you trying to run it on? It could be the OS X version on the SSD is too old to run on that Mac.

10,11 on the SSD and A 2012 2,5GHz MacBook Pro which has run it just fine previously

 

[Significant1]

Could be because you have used trim-enabler and the new computer has not signature check disabled. You can follow this guide to fix it:
https://www.cindori.org/trim-enabler-and-yosemite/
If you can boot on the old computer, you could probably also fix it using the new forcetrim command to enable trim with signature in place (I think the latest trim-enabler also use this command now, instead of patching)