Mail Merge Printing Problems

I started using mailmerge about 3 weeks ago and it all worked fine.
I went away for a few days. I probably updated the system. A few days later I went to print but it had stopped printing mailmerge

If I try and print mailmerge either to a file or to the printer neither works.

Saving to a file. = No file is created
Saving to individual files = A folder is created but no files.

Printing a standard document = Works fine
Printing a mailmerge = No printer dialogue box appears to select number of copies or other details and nothing gets printed

I have updated the system, re-installed libreoffice (it is up to date), re-installed cups, re-installed the printer driver.
Any help much appreciated.
Version: 5.0.3.2
Build ID: e5f16313668ac592c1bfb310f4390624e3dbfb75
Locale: en-GB (en_GB.UTF-8)
Running on PCLinuxOS minime X64 all up to date.

There is a possibility that this is an OpenGL/OpenCL bug (not fixed until end-December) (it affects printing to both paper + pdf, as well as display). Check at the reply to Q64314.