I started getting this error about two weeks ago. You can read about my experiences here:
https://www.mobileread.com/forums/sh....php?p=4445828
The short form is that you can't use ADE 2.0 in WINE anymore. The only possible explanation I found was that Adobe may have increased the security requirement to TLS 1.2, which ADE 2.0 doesn't support out of the box. You can't install the Windows TLS 1.2 security update in WINE.
Your options include:
- Switch to the Calibre DeACSM plugin.
- Try updating to ADE 3.0.
- Configure a Windows 7 VM with the required TLS 1.2 update from Microsoft to (maybe) make ADE 2.0 work again.
I chose option 1, and all is well again. You can still set DeACSM to identify itself as ADE 2.0, which lends extra credence to the TLS 1.2 hypothesis; Calibre has access to TLS 1.2 through the Linux OS, whereas ADE 2.0 doesn't have access to TLS 1.2 through WINE.