When trying to read a MemoryStream I got the following error message:
Here is the code I was using:
Couldn't be any simpler but unfortunately it didn't work.
I couldn't figure out what I did wrong...until I noticed the following in the documentation:
This constructor does not expose the underlying stream. GetBuffer throws UnauthorizedAccessException.
Aha, it seems that the OpenXmlPowerToolsDocument is calling GetBuffer behind the scenes. So we need to use a different constructor: