Rekordbox 5 with license key with DDJ SX yesterday worked fine, today as if DDJ SX is not connected

Please help.

Rekordbox 5 with license key with DDJ SX yesterday worked almost perfect.

Today rekordbox acts as if DDJ SX is not connected.

That is - look of the rekordbox is as if DDJ SX is not connected, only little thing that indicates that DDJ SX is connected is little volume knob in upper right corner that dissapears in rekordbox when DDJ SX is connected.

What to do to use rekordbox again?

Cable is ok, with serato DDJ SX it works fine.