After updating addons, le last progress bar stay on the interface.
It's just a visual bug, it doesn't block anything.
Currently : Minion 3.0.5 on Windows 10 Family version 1607 up to date.
You are correct that its just a visual glitch. It "should" be fixed in the next release as all our progress bar code was re-written. I can't say when the new version of Minion will be ready as its taking some time cleaning things up and switching to guice.