I am using Krusader v2.7.0 at the moment. It runs in the background the whole time I'm logged in.
When I LogOut, Shutdown, Reboot I've been getting a one time error message "Plasma Workspace (Logout) has been cancelled by "/usr/bin/krusader"and leaves me at the Desktop where a second attempt to LogOut, Reboot, etc works fine.
I'm assuming it's a Krusader thing and I don't know if it's only this version or also an earlier one. I'm getting the same error on three different Neon machines.
Any idea where to look to fix this? Not a major problem but it is mildly annoying.
I'm using the User Edition Neon 15.3.3 on all machines. Probably should also hit the Krusader forums and see if anyone is having a similar problem. DuckDuckGo hasn't helped to this point.

Some things to try to help with nailing down where the problem is:
Try disabling the option and/or killing krusader before logging out.
Try it in different environments (gnome, bare window manager) - make sure krusader is running before logging out.

It sounds to me like it is either specific to Krusader (could happen when in other environments), or it could be an interaction between Krusader and KDE/Plasma.

As a stop-gap, you could set up a script to kill krusader on logout.

Definitely Krusader. If I Quit it before trying to LogOut or whatever things work normally. This has been going on for a few weeks. May have been a Krusader update that started this. It'll probably sort itself out over the next while. Minor annoyance that's all. Incidentally, this has carried over to the Bionic update as well.