Trim, extend and parallel lines not working any more

I've been working with LibreCad for about a year.  Today I tried to offset a line and it would not work.  I tried to trim a line and it would not work.  When I tried to extend a line it said entity not found.   I am using windows 7.  I uninstalled the program, defraged, rebooted and reinstalled and still there is a problem - even with a brand new file.

I then installed LibreCad on my new WIndows 10 laptop and it worked perfectly. I brought in the file from my Windows 7 laptop and no problem.   What is causing the issue?  Is there a default setting that is corrupted in my Windows 7 laptop?

Thank God it works on Windows 10 as I'm not too keen on learning a new program and starting over!

BTW this is the first time I have been on a forum!  Perhaps you can teach an old dog new tricks.....

You may try and go to Options - Application Preferences - Defaults - Clear Settings - Layout or even All.
Reinstall doesn't remove settings in the registry. You could delete these manually if you have the knowledge or use a portable version from portableapps.com, which doesn't use the registry.

Else no idea what could be the reason.