Four icons in the dock on my girlfriend’s 2016 rMBP were replaced by question marks. The tool tips were still correct, but clicking the question marks did nothing.
In the Applications folder, I found the apps, along with an alias for each.
Dragging the question marks out of the dock removed them, and I dragged the apps back into the dock. Also deleted the aliases in the Applications folder.
The apps affected were Chrome, Word, Excel, and PowerPoint.
Do any of you know what might have caused this?