Previous versions had Projucer display a modal dialog when your projucer project had been modified. This happens to me all the time when switching between source control branches.
In JUCE 6, the modal dialog has been replaced with a tiny panel in the lower left. It’s a bit hard to see, but worse is that it is not modal, and lets you hit the “Save and Open in IDE” button. Not only does this let you export the wrong version of the project, it is also saves over the current project, which then is easy to overlook and accidentally commit the change.
It would be nice if projucer disabled “Save and Open” until you hit one of the Save/Reload/Ignore buttons in the lower left panel.