Are you being asked for a password?
Most likely you are in a Mac OS and your eDiploma.pdf automatically opened with Preview. You may be trying to save or move it with Preview.
Simply close Preview and go to downloads where you will find your eDiploma.pdf. You can use Finder to move the eDiploma.pdf to a folder of your choice.
Are you trying print your eDiploma?
By design, printing of your eDiploma is disabled. A self-printed copy of your eDiploma cannot be verified and should not be accepted as proof of your degree by employers and other institutions. If, for some reason, you need to print a copy of your eDiploma, you can do so using the screen capture method.
See the following links:
Windows Screen Capture
Mac OS X Screenshot
Ubuntu Linux Screen Capture
Issues uploading your eDiploma PDF to a website.
By design, your eDiploma is a Adobe Signed and Certified pdf. Because the pdf is encrypted, there are websites that do not support uploading a digitally signed and encrypted pdf. In this case, it is best to simply screen shot (.jpg, .png, etc.) the eDiploma and upload the screen shot.
Issues Combining and Inserting into an existing PDF.
Because the pdf is encrypted, in Adobe Acrobat, you cannot Combine or Insert your eDiploma into an existing PDF.
However you can, in Adobe Acrobat, Attach a PDF or use the Portfolio feature to arrange multiple pdfs into one document.