Hi everyone I've long had a problem with being unable to open some PDFs that could be either viewed on Windows or on Google Drive. For some reason, some PDFs appear to be encrypted (but not requiring a password??). Today, I found an approach that allows me to access these files also on my Linux machine using pdftk. pdftk allows you to decrypt PDFs by supplying a password (https://www.ubuntumint.com/remove-password-from-pdf-on-linux/): pdftk <protected>.pdf input_pw <password> output <new>.pdf However, the following seemed to work on these weird PDF files, without having to supply a password: pdftk <protected>.pdf output <new>.pdf And now my PDF viewers (okular, xreader, etc) no longer complain that they can't open the file. :-) Cheers, Peter -- Peter Reutemann Dept. of Computer Science University of Waikato, Hamilton, NZ Mobile +64 22 190 2375 https://www.cs.waikato.ac.nz/~fracpete/ http://www.data-mining.co.nz/