Using MEP Premium - just installed today. Last line of log file says: DBK BurnProject: 10 - movie encoding failed. Working on Windows 10 machine with an EVGA GeForce GTX 1060. My MB is a GigaByte GA-H97-D3H. Windows 10 is fully updated (in fact just freshly installed).
Video is only about 4 minutes long with a minimum of material, although that shouldn't be it, because the failure occurs immediately after hitting the burn button.
Additionally, a little two pic timeline was tried with file encoding only (no burn). It started to encode, but failed with errNo 13 - menu rendering failed. The menu was created by MEP as a single entry (the choice given before doing the burn).