Thanks for the reports. Apparently, there is a problem with encoding audio via ffmpeg to ogg.
Mac:
1. The log you posted only contains conversions, but no actual error messages. Is there more?
2. For long logs, please use a nopaste service like
https://pastebin.com/ and then only post the link.
Windows: "failed to run" can mean a number of different things.
1. Why is your ShiVa 2.0 Editor installed in "Program Files (x86)"? Are you actually running the 32bit version? Can you download the 64bit version and check if you have the same issue? Or are you rúnning the 64bit version and just installed it there?
2. Is some additional software (like an aggressive virus scanner) preventing ffmpeg.exe from executing?
3. If you run the ShiVa Editor as Admin, does it make any difference?