When I started Fusion 360 yesterday, all my projects were set to "Read-Only", and I could not change any to "Editable". After poking around a bit, I clicked on user icon (very top right) and selected "Autodesk Account". It immediately took me to a web page requesting I reset the Autodesk password.
After resetting the password and re-launching Fusion 360, I was able to set projects to "Editable" again. Just posting this here in case somebody else comes across it.
