I have the same issue. I'm using v2.2.0, Win 10, with a mouse and a 300kb file size, 4 layers all unlocked. I can't select entities on trim or parallel (maybe others as well but those are the two I know have issues). I believed it was a snap selection issue but I've tried every combination of snap and I'm still not able to select an entity to trim or parallel. I have been using LibreCad for years and still had v1.0.4 on my computer so I opened the same file with that older program. Both trim and parallel work flawlessly. I also have versions 2.1.2, 2.1.3 and 2.2.0 on my computer and have tried all of them and the only version that appears to work is the older 1.0.4. I have other older files that I've opened in the new version and have the same issues - won't let me select an entity. Has anyone else tried using an earlier version to see if it works on their files? And, does anyone have a suggestion regarding how to get the newer version to select an entity for trim & parallel? Any setting I've overlooked or haven't tried?
PS - Thanks to all of those that have worked diligently on this program. Other than a few issues, it works well for my small project uses.