maybe somebody has the same unpleasant and disturbing problem while using MCP 4:
When often switching from Mathcad to another program, the blue area of the menue bar gets thicker and thicker.
I wonder why software developers make such a crap.
I have no clue, and it does not happen in my situation.... at least, not with a few switches (ALT-TAB). How fast does you bar grow?
Does it also happen when Prime is not maximized (using the full screen)?
What OS (Windows 7, 8 or 10)?
Please send your issue to PTC's tech support by using "Mathcad Support Center" (you can do it, even if you use Express version of Mathcad Prime):