As soon as I drag and drop an email to a tab I lose the context menu until I
restart Thunderbird. Thunderbird version is 38.2.0

Created an attachment (id=8091) [details]
patched error console (console2)

please install the patched version of error console then open it with tools >
error console and configure as follows:

1st toolbar: show errors,warnings,messages
2nd toolbar: show JS and chrome (disable everything else)

restart Thunderbird.

open and clear contents of error console.
do the first drag to QF tab (any errors / warnings / messages?)
do the second drag (where it doesn't work anymore) - again check for error
messages

you can right-click in the error console,select all and then copy the error
text and add to the next bug comment please.

Created an attachment (id=8092) [details]
4.2 pre 13

Please install the attached prerelease version

If there are no error messages / warnings etc., enable QuickFolders debug mode.
QF Options > Advanced > [x] Debug Mode

then *right-click* on debug mode and also switch on:
extensions.quickfolders.debug.dnd = true
extensions.quickfolders.debug.popupmenus.drag = true
  (apparently there is a bug when that last one is set to true, which I just
fixed now)

repeat the same test with these settings.

Hi Axel,

The new version seems to have fixed it. There are only messages now, no
warnings. And the functionality is working correctly. Thanks so much!

Matt