Comment 1 for bug 185951

I have heard mention of this bug before. Like before, I'm unable to reproduce the recursive error.
On my system, btnx-config shows the error dialog, then does like you suggested: it highlights the erroneous value. This stops the error from continuing.
What version of gtk and glib do you have?

I admit the keycode entry is not ideal, and will probably be reimplemented with the btnx-config C++ rewrite, which is under way.