I have lost the attach file link since last up date

This is a recently discovered bug. The symptom is that if you previously attached a file, but the previous folder now no longer exists because it was deleted or renamed, when you later try to attach a file using the Write window's "Attach" button, it will silently fail. That is, clicking the button will appear to do nothing. The bug should be fixed in the next release.

In the meantime, a workaround is to drag-and-drop the file onto the Write window, as you discovered.

Or, if you don't mind changing Thunderbird's Advanced Settings:

- In <Settings | General | Config Editor> search for: "mail.compose.attach.dir".

- The value (path) here must be changed to one that is still available (for example C:\).

- Close and exit Thunderbird, then restart it (this step might not be necessary.)

Not exactly a minor issue as it is one of the most important features of an email client, attachments. I spent a day and a half trying to resolve this, It happens not only if renamed or deleted file but if you use a USB stick as E drive for the source of an attachment it latches on to this E drive. In this case can’t even drag the C drive file. I think this needs an urgent up date.

As I said, a fix is in the works.

Both of the workarounds I cited above work for me, including in the USB stick scenario you described.