Understanding a bad parameter when trying to protect a PDF

What is the exact bad parameter message that you get? Can you share a screenshot or an event log?

In which operating stystem did you experienced this, and what is the Adobe Acrobat product version rthat you're using and its latest version update that was applied to it?

But I think the most important question is how the document was created or exported to PDF.  You can figure out this info by right-clicking on any empty area of your document and select "Document Properties".

In the dialogue box window that will open you will see below "Advanced" the software that was used to create this PDF.

Have you tried clicking on HELP, and "Repair Installation"?  just to rule out is not a problem with the Acrobat application per se.  That said, is this happening with every PDF or just that one?