Does attaching a file manually work? You are dragging an attachment into the body of a Composition Window?

The manual attaching method works just fine, only dragging an attachment to the body of a composition window that does not work at all.

Where is the file stored - the one you want to drag and drop?

Is it stored on computer or is it in a folder like 'One drive' which means file is stored elsewhere on a server? If in something like 'One drive' : Put file on desktop and then see if it gets added as attachment. Please report on results.

Where is the file stored - the one you want to drag and drop? Is it stored on computer or is it in a folder like 'One drive' which means file is stored elsewhere on a server? If in something like 'One drive' : Put file on desktop and then see if it gets added as attachment. Please report on results.

It is placed in local disk like C: or D: not on online sharing folder. Both of them (local disk and online sharing folder) does not work to do drag and drop.

The symbol Ø will appear on body composition window when we try to drag and drop the file.

I'm using Windows 10 I've updated to version 128.6.0esr to make sure I'm same as you. I have a simple small text file and a sqlite 5MB file on desktop for test purposes. Also on D: drive - files used for such test purposes Folders need to be zipped first prior to adding as attachment. Using following process all of the above worked to drag and drop into the composing area of a New Write message window.

Open Write new message Left click - hold down on desktop file drag over the content area of new message window I see a grey outline box appear with the 'Add As Attachment' text in middle of area. Release button to drop - attachment successfully added.

So far not able to reproduce, I'll try to find out if there are any cases of failure to add via that method. I do know if file is stored online etc then file needs to be stored on same computer in a normal regular folder or desktop.

OK - sorry for delay - this took a bit of digging around and testing things. I've just tested something and I can reproduce this issue.

I did this: Exit Thunderbird Right click on thunderbird shortcut and selected 'Run as Administrator' Open Write new message Left click - hold down on desktop file drag over the content area of new message window The symbol Ø appears on body composition window Unable to add as attachment.

So yes I can reproduce but only when using that method to start up Thunderbird.

So I checked the 'Task Manager' info:

I run UAC with User Account set as administrator. But.... If I right click on Thunderbird shortcut > Properties > Compatibility and select 'Run this program as an administrator' Task Manager > Details - right click on explorer.exe > 'Set Priority' says 'Normal' and the column UAC virtualisation says 'Disabled' Task Manager > Details - right click on thunderbird.exe > Set Priority says 'Normal' and 'UAC virtualisation' says 'Not allowed' In Thunderbird you cannot drag and drop to attachment.

However.... If I right click on Thunderbird shortcut > select 'Properties' > select 'Compatibility' tab and UNCHECK: 'Run this program as an administrator' Task Manager > Details - right click on explorer.exe > 'Set Priority' says 'Normal' andcolumn 'UAC virtualisation' says 'Disabled' Task Manager > Details - right click on thunderbird.exe > Set Priority says 'Normal' and UAC virtualisation now says 'DISABLED' In Thunderbird you CAN now drag and drop to attachment.

So my advise is to try this: right click on Thunderbird shortcut > select 'Properties' > select 'Compatibility' tab and UNCHECK: 'Run this program as an administrator' Then click on the shortcut to start Thunderbird. Now try to add the file as attachment. Please report on results. If it works for you please make sure to set this comment as Chosen Solution so to help anyone else who has this issue.

OK - sorry for delay - this took a bit of digging around and testing things. I've just tested something and I can reproduce this issue. I did this: Exit Thunderbird Right click on thunderbird shortcut and selected 'Run as Administrator' Open Write new message Left click - hold down on desktop file drag over the content area of new message window The symbol Ø appears on body composition window Unable to add as attachment. So yes I can reproduce but only when using that method to start up Thunderbird. So I checked the 'Task Manager' info: I run UAC with User Account set as administrator. But.... If I right click on Thunderbird shortcut > Properties > Compatibility and select 'Run this program as an administrator' Task Manager > Details - right click on explorer.exe > 'Set Priority' says 'Normal' and the column UAC virtualisation says 'Disabled' Task Manager > Details - right click on thunderbird.exe > Set Priority says 'Normal' and 'UAC virtualisation' says 'Not allowed' In Thunderbird you cannot drag and drop to attachment. However.... If I right click on Thunderbird shortcut > select 'Properties' > select 'Compatibility' tab and UNCHECK: 'Run this program as an administrator' Task Manager > Details - right click on explorer.exe > 'Set Priority' says 'Normal' andcolumn 'UAC virtualisation' says 'Disabled' Task Manager > Details - right click on thunderbird.exe > Set Priority says 'Normal' and UAC virtualisation now says 'DISABLED' In Thunderbird you CAN now drag and drop to attachment. So my advise is to try this: right click on Thunderbird shortcut > select 'Properties' > select 'Compatibility' tab and UNCHECK: 'Run this program as an administrator' Then click on the shortcut to start Thunderbird. Now try to add the file as attachment. Please report on results. If it works for you please make sure to set this comment as Chosen Solution so to help anyone else who has this issue.

Thanks man.

Finally after a long time the problem is solved.