After connecting a new USB drive, the 'Safely eject' button doesn't work anymore. Nothing pops up. How come?

So, the button (system tray) is still visable, but right-clicking, left-clicking, or double-clicking: _nothing_ happens at all.

Looks like after connecting that new USB drive (TB), the whole options to safely remove a drive, stopped working entirely. (For _all_ drives.)

If I want to use "RunDll32.exe shell32.dll,Control_RunDLL hotplug.dll" to eject the external USB drive, it says: 'The ... device is not removable and cannot be ejected or unplugged'. It is a lie that it is not a removable drive.

If I use USB_Disk_Ejector from quickandeasysoftware dot net, it says: 'The disk could not be ejected. Close any programs that might be using the disk and try again'.

If the drive is in use, it must be by Symantec Endpoint Protection (it created the file 'System Volume Information\EfaData\SYMEFA.DB' on it), but I don't want to buy an other virusscanner and Symantec says it is by design that it uses that file and that it can't be deleted otherwise than deleting whole Symantec.

BTW, right-clicking on the file and using Unlocker 1.9.1, it says 'No locking handle found.'. So, it should not be in use.

Also, in Explorer, there's no button 'eject' or 'remove savely...' when right-clicking the drive letter.

Any other options to savely eject the drive?