Modded 1.12.2 server not launching after computer swap

[Cockathree]

So basically, I wanted to switch the computer that I was running my modded server on and to do so I took the SSD out and stuck it into a better computer, before I did this I made a backup on another hard drive that I haven't touched at all but the problem is that when I put back the SSD into the old computer it didn't launch the server and I was getting error codes when just trying to launch Minecraft. I had to hard reset my PC and right now all I have is a hard drive with the entire server folder copied to it and an old computer with nothing on it. Send help.