Lightroom CC on Mac Stuck Verifying Photos After Moving to New Mac

Hi,

I haven't been shooting photos so I didn't use Lightroom CC on my Mac and did not upgrade it for a few months. (Last time was May I think.) And in the process I have replaced my Mac but restored it from a backup using Time Machine.

Today I tried to launch it and it wouldn't launch. So I force quit it and got i updated via the App Store on my Mac. I use the App Store version not the Creative Cloud version.

And then it wants me to log in again which I did. Now its stuck on "Moving your photos"

"Verifitying your photos 0/30000"

With the option to stop and resume on next launch.

I tried waiting for 30min and so far it has no progressed at all.

If I stop it wouldn't show any of my photos in native res only the low res snapshot version.

I have checked the Lightroom Library.lrlibrary file and my photos are there in the default location. In fact when I use the examine pack content function on my Mac's finder I can go in there and open them in other applications. So its only Lightroom that's stuck.

So my question is how do I solve this? Is Lightroom's photo library bound to machine somehow? My old Mac was sent in for repair and the motherboard/CPU etc was all replaced so its effectively a new Mac with new serial numbers etc. But I did restore from an old time machine backup and everything else works as intended. Including other photo editing softwares. Just Lightroom CC's stuck.

If any engineers/customer support person can help it'd be much appreciated, thanks!