Ive tried a few times using itunes , shift restore, then I select the file and get that message.
When I click more information it just takes me to the latest itunes store download , that I already have.
I have a "similar" problem
I have an series 1 ipad mini wifi.
It was running 6.1.3 No problems with any of my installed apps.
I have same apps on my iphone 4s so I updated that 1st.
All apps work ok.
Apple sent me a message that I needed to update the ipad mini. I've been resisting but on this...
Download and use DiskAid
DiskAid User Guides
Works like windows explorer. I got it yesterday and have been able to even add files into a couple of apps I had loaded on myiPad 1.
Bazzle