After you put the dashboard on the server, did you reload it on the server? We see that message if we try to look at the document before it has been reloaded on the server. (We also see that message if the section access on the document isn't working properly, but you said that you checked this already.)
Many Thanks Nicole.
In fact I already tried several times to do a ReLoad but after the script is finished it gives me a "General Script Error" in the log and in the Event Viewer I can see the message "An operation was attempted on a nonexistent network connection". Do you have an idea?
But as the script had been run completely (given an error only after the last table population) I thought that it may reload at least some of the data.
As for your answer I can see now that the problem probably is because of a non existing sucessful reload.