Overlay Icons missing in Windows

Hi Everyone,
I have generated a Customized version of NC client 2.6.4 in Windows. Everything has been working well and syncs are done properly.

The only problem I am having is the overlay icons are missing in the machine in which the client is generated.
Whereas, if the same setup is installed in another machine it worked perfectly.

Is this something to do with Version of Windows ?
@misch @camila @splitt3r