Hi Hypronost, I have been having some similar issues. As I am rebuilding custom palletts that also contain macro buttons written in 4r8, I am finding that for some unknown reason the custom Ui starts to loose buttons, as I am going through the rebuilding and creating new custom pallets in 4R8.
Heres the weird thing on top of that,
This broken UI works ok If I use another tool .
But If I open up the tool I was using when I made the UI, the UI is always missing buttons.
Also when this occurs my CTRL Z hotkey no longer works on that tool.
The good news is after I keep working on this eventually I seem to get the UI stable. With the customization I want, Keeping my fingers crossed that the set up stays ok.