- Are you importing from your Camera card Directly?
- Where are you importing them(what is the Destination set to in Lightroom) ?
- How many pictures are you importing?
- Make sure you are not working on the Files being imported in Finder or elsewhere when Lightroom is importing them.
- Also check whether it is stuck while Building Previews or Face detection is On.
Where/what are you copying from and to where? What connection??
Thanks for the suggestions - in fact I had already tried all of them - the real cause turned out to be a catalog problem.
The catalog was, in fact, a copy of my catalog from last year from which I had deleted all the pictures and done an exit/check/optimise. All seemed fine for the first 600 or so pictures to import and then it started to go SUPER SLOW.
- to take my slow catalog and select all pictures in it
- export to a catalog
- make a new catalog
- import from a catalog (the one that I had just exported)
Now it is all working fine. I need to reinstall and reactivate the plugins for Google and facebook but that is OK!