Preview freezes when trying to merge PDF files
When I try to add PDF pages to another PDF Document in Preview, Preview freezes and I have to do a Command Q to get out of Preview. Always worked great previous to macOS Sierra. Does this on both my iMac15,1 running macOS 10.12.1 and my MacBook Pro12,1 also running macOS 10.12.1.
Does not seem to matter where or how either PDF was created, it hangs on all types.
Any ideas?
iMac (Retina 5K, 27-inch, Late 2014), macOS Sierra (10.12.1)