After installing an update, pasting a hyperlink into an email while composing it no longer works.
Running Vista with all updates on an elderly Gateway laptop. After a recent update to Thunderbird (45.7.0) I tried to insert a hyperlink into an email by clicking the "insert a link, anchor, image" icon from the header above. This opens the usual window that provides two places to insert text, the upper being for "link text" and the lower for "link location." When I right click the "link location" box where I intend to paste a link, a small box opens that says "#AppleSignature." No idea where this came from. As long as the "AppleSignature" box appears, I can't proceed. The only way to make it go away is to hit Esc. If I don't right click the box I can type information into it, but this obviously is a clunky solution.
The only possible Apple connection I can imagine is that the email I'm replying to originated on an iPhone.
As I think about it, a Java update may have also occurred about the same time as Thunderbird, if that's somehow pertinent.
Opaite Mbohovái (1)
A quick search of the Internet finds nothing useful on this.
So I suggest that you paste the link in there using Ctrl-v, instead of right-clicking and choosing paste.
Ctrl-v: Hold down the Ctrl key on the keyboard and press the "v" key on the keyboard.