"npm run build" ends with error messages

[RolandReyer]

When I try to "npm run build" I get a lot of error messages and the process is aborted.

There seems to be a little problem in the file "package.json". When I change that line, the process runs much longer, but ends with different error messages.

I am quite inexperienced with Java Script, npm and with Github. It may well be that I have not understood something quite obvious.