Hi,
So far all of the problems I've seen with Windows 10 have to do with Windows 10 changing file permissions during the in place upgrade.
It seems to leave the main user account without permissions to many files in the documents directory (including BeerSmith) for some
users.
The correction is to make sure all of the files under Documents/BeerSmith2 are owned and writable by your main user account.
Here is a thread describing the problem (with pictures and such) after upgrade. The same would apply to the Documents/BeerSmith2 folder.
http://www.tenforums.com/general-discussion/9634-unable-create-save-files-documents-pictures-folders.html
Cheers,
Brad