Dear Qubes Community,
Many of you are upgrading to Thunderbird 78. The Qubes Thunderbird extension, which allows you to easily open attachments in DisposableVMs, has not yet been updated to work with this new Thunderbird release. You can find the details in this bug report:
However, while you wait for the extension to be updated, it is important to understand that this extension is purely for convenience. It is not required to do anything. You can do everything that the extension does manually. For example, to view an email attachment in a DisposableVM:
1. Save the attachment in your email VM.
2. Open the file manager in your email VM (e.g., nautilus).
3. Right-click on the attachment and select "View in DisposableVM."
The extension makes this more convenient by automating the process, but it doesn't do anything that you can't do yourself. Nonetheless, we are working on upgrading the extension as soon as reasonably possible.
Further discussion can be found on this forum thread:
(Attachment OpenPGP_signature is missing)