One of our users was running Windows 10 Home. She upgraded to Windows 10 Professional specifically for EFS.
She then went into each sub-folder under Documents and applied the encryption attribute using the same procedure. She did not get a UAC prompt.
Files that existed prior to the Windows 10 Professional upgrade that received the
Encrypt contents attribute are now scrambled. For example, CSV files (plain text following the CSV standard) when opened in Excel or a text editor display jumbled, mostly non-alpha content.
When the encryption attribute is removed from a given file, the bit pattern is unaltered. The same jumbled characters appear in the file.
Files that are created after the update to Windows 10 Professional seem to function normally.
What could cause this behavior, and how can we recover from it?