I had previously set up my iCloud calendar, contacts, and data. This was several weeks ago (I moved everything over from Outlook for Mac 2011). So far, so good.
Two days ago I set up my wife's iMac. Update all software, transferred her calendar info from Entourage (about 2007) on a 2007 MacBook running Tiger, to iCal on her MacBook. Then I imported the iCal data via an external harddrive into her iMac. I then imported that data into Calendar.Worked perfectly. Then I enabled iCloud via system preferences, allowed calender to merge , disabled her local calendar, and subscribed to a US holidays calendar. Worked perfectly. Then I clicked on the icloud calendar's broadcast icon, and set me up as sharing view only. Hit "done", and that's when the message appeared. I went to iCloud.com , logged in with her account, and tried to set up sharing the same way there. Different appearing message, but same message: server error.
I went to my iMac, and set up my wife as sharing, view only, for my calendar. She got an invitation email, accepted the invitation, and presto chango, she can now view my calendar.
Over 2 days, I've tried to get her's to work perhaps a dozen times, thinking it was a temporary server glitch...no joy.
I searched in Support.com, and found one similar message, but with no reply yet (was dated 7/16/13).