Problem opening DRM-protected PDF in Adobe Reader

Hello! I have an ACSM file, recently downloaded, and I used Adobe Digital Editions to download its content, so I got the PDF file protected by DRM. I can read it using the ADE programme, but if I try to open it by clicking twice on it, I get the following message (roughly translated into English): "Error opening the document. The plug-in needed to run this command is not available".

I'm using Adobe Acrobat DC (64-bit) 21.011.20039 and Adobe Digital Editions 4.5.11 in Windows 11 64 bits.

Any ideas? What am I missing? Can anyone help me? Thanks a lot in advance!