PDF export - Security tab issue

[Zaahir]

Hello,
I used to be able to go into the Security tab when exporting a PDF and restrict options.
These days it's all grayed out and I can't change anything.
Please tell me what I'm doing wrong, thanks!

in the Security tab if you have none checked in document encryption & permissions password, everything will be greyed out.
Check 40 0r 128 bit and it should work