I had to uninstall a program unrelated to Fusion and during the process Fusion was forced to close by the uninstall. When I opened Fusion after the uninstall was finished, I was, and am, unable to zoom in and out with the mouse wheel (no it's not the mouse, it works fine in AutoCAD). The program was an Adobe pdf generating program created by a third party by the way.
In addition joints that were working properly prior to the shut down act as if they are nonexistant. The joints are in place and were working correctly before this but now they have somehow been broken. I've gone back and opened a previous version of my model but with the same result.
Forth reboot and joints issue is no longer. This isn't the first time a reboot or two seemed to work when things go a bit strange.