This does not pertain specifically to VBA, but as an FYI:

I write a lot of scripts to automate Excel, but these are executed outside of Excel as macro code is not permitted in the .xls(x) files.

a typical script begins:

oXL = CreateObject("Excel.Application")
oXL.Visible = true
which now often fail with the Powerpivot and SQL DataMining add-ins.

adding

While ! oXL.ready
  ...a time delay
EndWhile
the problem is resolved.