Preview crashing

I've had an ongoing problem with Preview since updating to Yosemite. It will open but if I try to open any document or image it just crashes. I've searched everywhere for a solution and for a while I found one - copying the package contents from a working copy of Preview. I had a full backup of Mavericks on an external hard dive and copied the package contents from there. Worked perfectly.
Unfortunately, I backed up my MacBook Pro over the Mavericks backup, forgetting about the Preview problem and I'm back to square one. I also have a Mac Mini on which Preview works perfectly but copying the package contents from that doesn't work.
I've also deleted the Container and Preference files which seemed to work for some people.
Anybody had the same problem?
I just tested Preview in another account and it works fine. What's happening?

 

Found the cure!

Well, as soon as I had posted this question, I thought that the problem had to be in my Home folder so I started to search and, inside Group Containers, I found two entries - com.apple.Preview and com.apple.PreviewLegacySignaturesConversion. I deleted both and, hey presto, problem solved.
I hope this helps someone else.