Hi,
This could be for different reasons, that your system had an issue keeping up with the demands of the song and/or audio processing and couldn't write the output correctly for some reason. If you don't hear dropouts when playing, try checking the "Realtime" box in the mixdown dialog to see if you get a better result.
If it continues to happen, please make a tech support ticket and be sure to include a system information file so that the support representative will have enough information about your system to possibly immediately have a few good avenues to investigate.
OS X
To access your MAC's System Profile:
- OS X 10.11 (El Capitan): Apple Menu --> About this Mac... --> System Report --> File --> Save
- OS X 10.10 (Yosemite): Apple Menu --> About this Mac... --> System Report --> File --> Save
- OS X 10.7 to 10.9 (Lion / Mountain Lion / Mavericks): Apple Menu --> About this Mac... --> More Info... --> System Report --> File --> Save
- OS X 10.6 (Snow Leopard) or earlier: Apple Menu --> About this Mac… ---> More Info -->
File --> Save As
- Save it as "your_name.spx"
- Attach the .spx file to the support ticket email.
Windows
To access your PC’s System Information on Windows 7 and Windows 10
1. Click Start > All Programs > Accessories > System Tools > System Information
2. IMPORTANT: Click File then "Save as", save this file as a .nfo file format and rename the file your name and attach it to the support ticket email.
To access your PC’s System Information on Windows 8:
1. Go to the Desktop.
2. Press [WinLogoKey] + R to bring up 'Run'.
3. Type 'msinfo32' without quotes.
4. Press the [Enter] key.
5. IMPORTANT: Click File then "Save as", save this file as a .nfo file format and rename the file your name and attach it to the support ticket email.