Windows 10 Latest / Vegas Pro 16 Latest
Steps to repro:

• Load a project and bring up the Video FX window
• Add some effects
• Go to Save As in the plugin chooser
• After naming and saving your Plug-In Package, and hitting OK...
• Hit Cancel (or OK but it seems to happen more when Cancel is hit)
• 

I consistently get all other Windows coming in front of Vegas (ie. Chrome / Notepad etc. - anything else that is open) they block Vegas and Vegas must be brought back into focus by minimizing all the other windows.

Also it sometimes causes a crash, if project is subsequently closed.

Can anyone else reproduce this?