acsm file to the library so I can open and read that ebook in ADE but I really want to open and read it using Acrobat Reader DC but an error is displayed telling that there was an error opening the document because the protection plug-in required was unavailable. While DRM is all about controlling the user, open source software is about empowering the user.

Open source software and DRM are a clash of principles. At least, this is the rationale, but there’s much debate about how effective DRM actually is at its intended purpose. If calibre were to support opening or viewing DRM files it could be trivially modified to be used as a tool for DRM removal which is illegal under today’s laws. acsm ebook and also downloaded the corresponding drm pdf file (located in the 'My Digital Editions' folder). DRM is meant to make unauthorized copying of digital content harder, dissuade piracy, and protect the financial interests of the creator.

I have installed on my pc Acrobar Reader DC and also A.D.E 4.5 both upgraded to the last version both logged-in with the same (my) Acrobat ID.

Drm removal pdf