Hope this helps if you havnt resolved this issue yet?
I have been having the same problem with a report and getting the same error message!
Just before i was about to rip the report out and start allocating document cals again like a mad man i deleted the .meta and .shared files from the folder and tried the QEMC again and now it works fine!
However odd it seems to have resolved the issue!
Problem has been fixed. I copied the .qvw, .meta, and .shared files to our test server. Didn’t get the error message when I went to User Documents tab. But I did notice that there were some server objects associated with 2 logon ID’s for people no longer with the company. I deleted those server objects and copied the .meta and .shared files back to production. That cleared up the problem.