Dedrm_plugin.zip
: DRM removal only happens at the moment a book is imported into calibre. It will not work on books already in your library unless you remove and re-import them.
Invalid Plugin does not contain top-level init.py file #1076 - GitHub DeDRM_plugin.zip
ElleKayEm commented. ... After you unzip DeDRM_tools_6. 7.0. zip, rename the unzipped folder something like "unzipped DeDRM tools" : DRM removal only happens at the moment