hi, using 45.5.1 thunderbird on windows 10. i use a separate html file for my signature (with the "attach the signature from a file instead" option checked). whenever i compose a new message, the image in the signature appears. but when i reply or forward a message, the signature image displays an empty box with a broken link logo. when i double-click the empty box, i toggle "attach image to this message" in the image properties dialog, then click OK. the image now appears. why won't the signature image appear automatically? i've configured settings so messages display HTML automatically. have also ensured that the signature attaches automatically to replies and forwards. any help is greatly appreciated. thanks!