It may appear to be an Xorg or lightdm/gdm/mdm error but in reality for many users with this issue, it's a driver conflict and issue. I had a system that had two GPUs, an Intel and Nvidia GPU.
The only thing that got it working was to remove the nouveau driver and blacklist it so it never came back, then the Intel GPU works fine without these issues.
Solution
sudo rmmod nouveau
add nouveau/other driver to blacklist
edit th........
catdoc.i386 : Decodes MS Word files into plain text or TeX format
I haven't figured out how to use it, it is really not clear or obvious but it should do the job if you can figure it out.
Usage:
catdoc [-vu8btawxlV] [-m number] [-s charset] [-d charset] [ -f format] files........