Under customizing quick tools, I've added the protect -> Encrypt item to quick tools. When launching a new PDF I can easily click the padlock and choose 2. encrypt with password on my PDFs.

However, if you go to Edit then Preferences, under the general category, uncheck 'Open documents as new tabs in the same window (requires relaunch)'. Close and reopen any PDF, I can no longer choose 2. encrypt with password. Can you please fix this bug