Unable to drop update file in Elektron transfer

Using windows 10 and trying to update Analog rytm mk1 (OS 1.50)… just downloaded and installed the latest “Transfer” program.
I open it and choose the Rytm midi in/out in connection and it shows a green box (seems its connected)
When I unzip the OS file and try to drop the .syx file, it shows a “block” error icon, the background is not highlighted and the fileis not visible there.
Any idea of what’s the issue here?

Many thanks!