I downloaded this program so that I could add a password to my tax documents. It worked for most of my files but it failed on a file downloaded from my broker.
Encrypt – PDF Shaper Professional
Files: 1
Process initiated…
File #1
C:\Users\%username%\….\2017 5498 Vanguard.pdf
Loading… OK
Document changes: Not allowed
Content changes: Not allowed
Unable to encrypt file… Error