As far as we know, this issue only occurs on Windows OS, the reason being is usually related to application or user's permission. There are two ways to fix the issue:

The reason may be related to the user permission setting. It could be fixed by modifying the Windows registry. the steps are shown as follows:

Don't run Eagle as "Administrator"

Normally we wouldn't need the "Administrator's permission"' to run Eagle, Doing so may cause inconsistent permissions between Explorer and Eagle, thus making drag-and-drop unavailable.

modify the Windows registry.

If you are sure the issue is not because of the "Administrator's permission", we could try modifying the issue to address it.

Click on the Windows icon in the bottom-left corner and search for "regedit".
Click "regedit" to run the registry editor.
Go to the directory to modify EnableLUA value
Find the directory on the left and click sequentially HKEY_LOCAL_MACHINE > SOFTWARE > Microsoft > Windows > CurrentVersion > Policies > System or directly enter Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System in the path column.
Modify the EnableLUA value.
Find the EnableLUA in the list, open it and change the value from 1 to 0, then restart the device, re-open Eagle and try to see if the issue has been solved.

If the above solutions still don't work, please contact us.

I can't drag to add files, the app showed unavailable icon