Oct 13 2016 04:32 AM
Here's where I posted the original issue... http://answers.microsoft.com/en-us/msoffice/forum/msoffice_excel-mso_win10/power-pivot-suddenly-unab...
This was the closing response in July 2016:
"I’ve checked with the related team. Our engineering is aware of this issue and they are working on it. Please keep your Excel up to date.
I then noticed that my Surface Book started working a while later