Did you upgrade to Windows 10 from an earlier version of Windows ?
If so what is the spec of your computer, If you have less than 4Gb ram this could be a factor as windows 10 requires more ram than earlier versions.
As you say it happens after about 3hrs into your show I wonder if you have picked up some malware or a virus which is working in the background.
Windows 10 normally downloads monthly updates of the Malicious Software removal tool. If your not seeing these updates I should download the tool from:
https://www.microsoft.com/en-gb/down...l-details.aspx
Also run a full scan from your virus checker program.
Other than that there are settings in Hoster for audio dropouts but I expect you have gone through those.
1) if your running in Tempo mode try turning that off: Tools Menu/Settings/Tempo switch to (normal mode)
2) From the Tools Menu/Settings/Audio the prevent audio dropouts box the default is 10, raise it higher, try 15 for a start also below that is another setting to change priority of graphics and audio try changing them, exsperiment to see if raising the audio priority above graphics helps or visa versa.
If none of the above helps or no one else answer your query I should put in a support ticket to MTU:
http://www.mtu.com/support/contact-us.htm#HelpTicket