I have a draft document (copyright, & therefore not attachable) which have to
precis.

I turned on record changes using the menu (is there another way)?
I cut out various chunks.
I then unchecked "show changes" so that they were hidden.
I then did a search and replace, looking for double space and replacing it with
a single space.
Writer crashed immediately.  It asked for a crash report, which I filled in and
sent, but at this point I hadn't realised it was linked to the search and replace.
On trying it a second time, and crashing a second time, I made the connection.
To test my theory I accepted all changes and then performed the search and
replace, no crash.

I have searched for this issue and am a little surprised not to have found it
already reported, so perhaps it's just my poor searching.  If so, I apologise.