Attempt to drag a message drags entire window

[bburd]

After installing macOS Sierra, I'm often unable to drag email messages to folders in the folders list. When I try to drag a message, it drags the entire Thunderbird window, even though my mouse cursor isn't on the window's title bar. Any help for this?

[tanstaafl]

See if the problem is due to an add-on by trying again after "help -> restart with add-ons disabled". See if rebooting your computer helps, I've found old threads with the same problem (using Linux though) where that solved the problem.

Is there any pattern in what messages this problem occurs with, or is it random?

I suggest you also experiment with configuring Thunderbird to open a messages in a tab instead of a window and see if it makes a difference.

[bburd]

Add-ons disabled seems to fix the problem. I'll add them back one by one to find the culprit. Thanks.

[bburd]

Now it's happening even in safe mode. That's one of the weird things about this problem. When it happens or doesn't happen is unpredictable (or, at least, I can't predict it.)

[TimJF]

I get the same problem with Sierra install. Some parts of the main compose window cannot be dragged around the screen when either composing a new mail or moving the main window. I have tried altering transparency with no effect. Also sometimes I cannot drag and dump attachments to desktop as it moves the whole window.
I am using iMac 27 inch late 2012, sierra 10.12

Is there a fix please?

[TimJF]

I get the same problem with Sierra install. Some parts of the main compose window cannot be dragged around the screen when either composing a new mail or moving the main window. I have tried altering transparency with no effect. Also sometimes I cannot drag and dump attachments to desktop as it moves the whole window.
I am using iMac 27 inch late 2012, sierra 10.12

Is there a fix please?

[tanstaafl]

I don't have a Mac, so I can't try to reproduce the problem. I haven't noticed any other threads about it and couldn't find a relevant bug in https://bugzilla.mozilla.org/ . Did you experiment with using tabs instead?

[TimJF]

Can you let me know what you are thinking by experimenting with using tabs please?

[tanstaafl]

Tabs are dragged quite differently from windows, so knowing if they are effected may help in trying to figure out whats going on. You might also find it a useful interim workaround.

[TimJF]

All of my new message are started in a new window if that's what you mean - these are showing signs of not being able to drag. If you wish I can try and take some footage of the problem which is inconsistent but will show what is happening. I think I would need a email address and will send via WeTransfer or something?

[bburd]

I just had the experience where I couldn't swipe my mouse to select text. When I tried to do this, it moved the Thunderbird window instead of moving my mouse along the text. As a temporary fix, I'm always running Thunderbird in full-screen mode. That way, the Thunderbird window can't move when I hold down my mouse button.

[pohjois]

Same problems here. It's extremely annoying. Also have found that people on google macos forum complain about the same problem.

[Mmhrd]

Have the same problem - after upgrading to OS Sierra. Disabling Add-ons does not solve the problem.
However, opening the email in another tab solved it. But this is irritating.

[bburd]

The only workaround that I found for it is to always make the Thunderbird window full-screen.
P.S. I'm sure that it's a macOS Sierra problem because it has happened again exactly when I install Sierra on a different computer.

[tanstaafl]

I suggest you file a bug report at https://bugzilla.mozilla.org/ since I can't find any similar bug reports. If you do that please post a link to the bug report.