Which version of Sound Forge 15? Is the DJ mix coming from an external playback device? Is it an analog or digital input? Can you otherwise hear the sound on the destination PC? We need more details to help you. Read the 'Sticky' at the head for the main Sound Forge forum page.
btw @bernard-hill2470 you only need to post your query once. Please delete your duplicate posts. Otherwise welcome to the Magix Sound Forge users forum.
soundforge 15 version 15.0 build 47 the dj mix is coming from virtual dj digital input i can hear the sound but its not recording into the soundforge while playing
Sound Forge 15,.. Audio Studio or Pro? I think build 47 is Audio Studio (AS). In any case, confirm your DJ mix source is set in the "Options> Preferences> Audio> Device type record". The settings for Sound Forge AS and Sound Forge Pro may differ some.
the dj mix is coming from virtual dj digital input
I wonder whether you mean the audio is coming from the digital output? If so, exactly how are you connecting the output to your computer? Does your computer have a digital input?
Microsoft Sound Mapper or Windows Classic Wave driver are usually trouble free,
If the 'DJ mix' is an application in the same PC, you may be able to 'record what you hear'. Some PCs (Dell for instance) can do this natively. In the Windows 'Control Panel> Sound', under the "Playback" menu tab, enable "Speakers / Headphones". In the Record tab menu, enable "Stereo Mix". The PCs volume control will act as the record level setting.
'Speakers / Headphones' and 'Stereo mix' are typical of Dell / Realtec sound cards, others may use different terminology.
If your PC cannot nativly 'record what you hear', there are sound utilities available.