Warp Stabilizer error: unknown exception

I'm trying to edit simple videos: no audio whatsoever, color and light correction only, speed/duration, and stabilization (previously nesting the clip for it to work). 

I have done this type of editing before and never had any issues. 

But since yesterday every time I try to use Warp Stabilizer tool an error pops up: 'unknown exception on frame 0 in Warp Stabilizer'. 

I can't find any help online, I have nested the clip, I have changed the scale, I have uninstalled and re installed Premiere Pro, updated.. everything I can think of. But nothing helps. 

Has anyone experienced this before?

I'm using a Macbook Pro 2019 and working with an external hard drive. 

Thank you.