Oh, hs2, I see that you took it lightly - they have to be hitting a wrong key.
I can confirm that copy to clipboard intermittently fails. I use 18.0.1.2 (not 19) with all the hot-fixes and this problem was there from the very beginning. I'm not sure about earlier versions - I think it started in 18. I don't remember seeing it earlier.
It doesn't matter what key is bound to what. It doesn't matter what type of copy it is (CHAR/LINE). And the message "line copied to clipboard" is not reliable. It also doesn't matter whether the clipboards tool window is open or not. However, when this window is open we can better see what is (or is not) happening.
So, let's say the clipboards tool window is open.
1. We do a copy to clipboard hitting a shortcut key or executing, from a macro, something like this::
push_clipboard_itype('CHAR');
append_clipboard_text("xxxxxxxxx");
_copy_to_clipboard('', !__UNIX__);
2. In the clipboards tool window we can see that the copied text went there and is shown as the last clipboard. Up to this point it all seems to be fine.
3. Now we want to paste it. From time to time the paste doesn't work as if there was an empty string in the clipboard (but we see the valid text on the top of clipboards). It doesn't matter where we paste - within SlickEdit or outside.
This doesn't happen often. If it did, I would move to another editor. It seems to be completely random. Sometimes it occurs five times within ten copy/paste sequences and then it works fine for three days for hundreds of seemingly identical cases. It's like a variable was left without any initialization with the garbage value being most often right.
I see that the person who started this thread is using the Brief emulation mode. I do too. This may be the clue. Not too many people use this emulation these days and it was getting worse and worse in every SlickEdit release.