I'm checking the copy editor's edits on my most recent book. The document is about125,000 words long and all the edits have been done using "track changes", so I can see them and respond. On my home PC the document was freezing every time I made an edit. I kept getting "Not responding" and had to wait for a second or two before I could make the change. I opened the same document on my work laptop this morning: no problems at all!