I get the same output log.

Yes, I did a npm install in the folder and yes, it seems that the parser is installed. I have a folder named ~/MagicMirror/modules/MMM-Skolmaten/node_modules/rss-parser with this content:
.npmignore
.travis.yml
LICENSE
README.md
bower.json
browser.js
dist/
index.js
lib/
package-lock.json
package.json
scripts/
test/

Thanks for looking in to it!

Thanks, that did it!