Can no longer read some old DeDRM'd ebooks

[jpaulm]

This is a long shot, but I'm hoping someone can point me in the right direction... I have a few old epub files which I was able to read on Calibre 2.0.
I have upgraded my PC, upgraded to Calibre 2.76, and reloaded DeDRM software. Now, even when I use the old Calibre with the old Calibre Library, I can't read the books that I used to be able to... Does anyone have a suggestion how I can get these ebooks back? Is there a tool which would show what is wrong (if anything) with these particular books?

FWIW Running Calibre-debug with --gui gives following:

Could not decrypt rcxp57.epub. Wrong key
DeDRM v6.5.2: Failed to decrypt with key default_key after 0.1 seconds
DeDRM v6.5.2: Looking for new default Adobe Digital Editions Keys after 0.1 seconds
Found 1 keys
DeDRM v6.5.2: Ultimately failed to decrypt after 0.1 seconds.

TIA

[PeterT]

To my eyes this says the files are still drm'ed. Maybe try asking on Apprentice Alf's for assistance.

[stumped]

the clues are here
I have upgraded my PC and
Wrong key
DeDRM v6.5.2: Failed to decrypt with key default_key after 0.1 seconds
DeDRM v6.5.2: Looking for new default Adobe Digital Editions Keys

Seems you have changed/ lost/ uninstalled the free ADE key. [ your ADOBE ID ]. you can get that back my logging into adobe web site, if you can remember the email that you would have used before
you are looking for an Adobe ID which would have been written into the registry of your PC. That survives most things , though, so it is strange that you don't have it.I did not lose mine when I upgraded from windows 7 to 10 .
A fresh install of Windows would have wiped it. it is possible you have more than one ADE ID and you need to install the one that matches those books. AFAIK, a PC can only store one such key.
try here & use the forgot password option. ( but you have to know what email account you used to use )
https://helpx.adobe.com/nz/x-product...nt-change.html

[theducks]

Moderator Notice
Reminder: MR policy does not allow discussion on debugging DRM removal

[DoctorOhh]

Originally Posted by jpaulm

This is a long shot, but I'm hoping someone can point me in the right direction... I have a few old epub files which I was able to read on Calibre 2.0.

Since calibre only reads books without DRM any old books in your calibre library that you were able to read via calibre previously, you will still be able to read currently since they did not have any DRM on them. Restore the old library from backup and you should be fine.

If you are having trouble removing DRM because you are trying to re-add all of your original books then we can not provide detailed steps and as suggested above you need to ask for help were you got the plugin.