Hello: w11p auto updated, tbird dev build 128.5.2 esr 64bit (only, no stable here!), so...1) I DON'T know if this is a "my" problem or a bug. I also don't know if this issue happens in stable. So, 2) Do I HAVE to use the top menu item - message>attachments>delete- (the attachment is already hilighted)? What I needed to do: modify the already-attached pdfs to add signature. -History: I learned the hard way that (apparently-- note the "me?" or bug, & dev build, above), that drag & drop* do not work. Moving on from that, I tried merely 1- highlighting the attachment, & hitting the delete key 2) using the R mouse button & using the "delete attachment" choice. 3) I may have tried other things but geezer excuse, sorry, I can't remember what else. They all failed, the attachments remained. 4) I ended up just creating a new msg, pasting the msg body into that new msg & editting the pdfs using Mozilla pdf built-in editor (Note: THANKS VERY MUCH, MOZ STAFF, FOR IMPLEMENTING PDF EDITOR!!!), then re-attaching the pdfs (always for this prob, as attachment). *ideally, what I wanted to do was merely drag the attachment to the desktop, edit it, then redrag & drop the editted pdf back into the t-bird attachment pane, and tbird would recognize this modified file & replace the old unmodified file w/the modified one. Absolutely no go on my try on this. (By "no go" here, I mean that the modified file wasn't there. The original pdf w/o signature stayed, the modified pdf w/signature added never got into attachments. File name remained the same.) So, what do I want ? Simply for context & other non-top menu items to work, to mod or delete a file in attachments. Thank you, stay safe.