id: 1200 the reason is: ErrorEvent error Failed to load prezi from template xml.

There are some topics concerning same problem. I had same problem on my Mac. I tried updating flash, Air and checking my security software. But nothing was changed. I finally solve this problem by deleting .plist and related files and folders in
/user/username/library/preferences/
and restarting.

I was a user of PreziDesktop3. I may think some old files make a problem.