I, too ,have this same problem, but with Stitcher 5.7.1. (Stitcher Unlimited 2008)
I was using this copy of Stitcher for 10 months on my new Mac laptop, and last week got a pop up message stating that my "Trial period was ending in ten minutes." Whaaaa? I paid for a license arond 2009, and successfully stitched several tens of 360ºx360º panoramas. Now, it still works, but it will not save and the output has "Autodesk" watermarks all over the render.
I suspect that one part of the problem was that months ago, I attempted to install an upgrade, Stitcher Unlimited 2009, which failed activation because I could not connect to the Autosdesk®servers. It would try to connect and after up to 5 minutes just crash the software.
That was ok, because Stitcher 5.7.1 continued to work.
Until I double-clicked an .rzs (Stitcher doc) file and it opened SU 2009 software.... still in trial mode. I quit that and started to use SU 5.7.1 and then a couple of days later I got my problems.
At least all I want is my Stitcher 5.7.1 to work as it did for the past six years.
Autodesk Support seems uncertain of how I should proceed. I guess all the people on Stitcher went to other, more profitable, Autodesk products and there is no one left who really knows what I should do.
