If distributed rendering does not work and you can see this error in the command line window:
Error rendering frame 0: Unknown error while loading application
Job Completed with Error(s) - see above
Note: Autodesk Backburner is not used in Corona Distributed Rendering but it may sometimes block required 3dsmaxcmd.exe from running.
1. Uninstall the older version of Backburner.
If you encounter any troubles during uninstallation of Backburner (for example "Error 1722"), download and run this tool: http://support.microsoft.com/mats/Program_Install_and_Uninstall and follow on-screen instructions (usually: Accept, Detect Problems and let me select..., Uninstalling, find old Backburner version on the list, Next). After doing this, you should be able to completely uninstall Backburner using Windows "Programs and Features" window.
2. After uninstalling the older version of Backburner, make sure you have the newer one installed, or re-install it.
This should fix the issue. If it doesn't, and you didn't find any solution in Distributed Rendering troubleshooting, please report the problem to us. See: How to report issues?