Update in the Context Menu issue.
This was actually a rather subtle problem to resolve!
My initial installation of Multi Commander was on a Windows Vista box, where, as reported, everything seemed fine except for the context menu issue.
Before trying to resolve any issue with extension incompatibilities I decided to install Multi Commander, (64 bit version), on one of my Win 10 boxes which carries very similar software content .
Result - on that computer, the context menus worked every time.
With that confirmation that at least one version was working on my local network I then compared the content of the context menus on each box. This was identical apart from one specific piece of software which exists only on the Vista box.
So, following you excellent advice, I installed and used
ShellExView and disable that item.
Result. Multi Commander still crashed.
It was then a matter of selectively disabling / enabling any relevant extension to try and remove the problem. Nothing obvious worked until, almost as the last try before giving up I checked the AVG Shell Extension Class.
(I use AVG antivirus on all of my computers after many years of Norton and then a few years of unhappy experiences with McAfee).
This extension did not cause any problems on the Win 10 box and the context menu functions quite properly, containing the "Scan with AVG" and "Permanently shred with AVG" options. Both of these originally appeared on the Vista box too but disabling the extension removed them of course.
Basically, with the AVG extension removed on the Vista box, the problem appears to have been resolved.
Update on the change Look'n'Feel issue.
This issue was much simpler to resolve. Using the "Quick Look'n'Feel Setup" option the selection panel appears, of course, but there is no indication that once a change, say from Commander Style to Explorer style has been made it is necessary to close down and restart Multi Commander for the change to take effect. If the information is somewhere I didn't see it, but I suppose the solution is obvious, in hindsight!
Update on the File Coloring Rules Editor issue.
No solution yet as to why the error message "
Your color setting in Explorer Panel does not allow for Rules Based coloring. To see this color rules in use you must enable that option." appears. Even in the new installation on Win 10 the message appears even though no configuration changes have been attempted.
Just where is the option to allow for Rules Based coloring? I have looked carefully and can't see that anywhere.
Thanks for your help; as I posted originally, I was, and am, impressed with the quality of this utility!