Three of us in my office have the same issue with the calendar icon disappearing. I also get the same message as Rosalyn Leach about not being authorized and then I have to go back and recreate the Query. Huge waste of time and so frustrating. 

Yes, this started about a week ago.  I find this system VERY FRUSTRATING and this just adds to the frustration.  I am also enjoy setting up a Query and pressing Run Report and getting a message that says that I am not authorized.  I am the Administrator.  When this happens I then need to go back and order the Query again from scratch and then it works. VERY FRUSTRATING!

I am having that issue as well. 

I've also been having this problem, along with disappearing scroll bars that do not return. VERY FRUSTRATING