Never mind solved it

I read that Action can have issues with Sweet FX, I guess this is still the case.

I was running Sweet FX, so I disabled it and Action runs fine.

If using Sweet FX I recommend the Sweet FX configurator tool or JSGME as that way they can be easily enabled or disabled as required

Same symptoms as the Minecraft thread

Apologies for first post being a cry for help, just never had issues before. Its been a while since I used it and it performed an upgrade, prior to this Action has always been fine with no problems