Homeassistant wont start after installing mqtt

Hi

i installed hassbian on my raspberry 3b, then i updated using , ssh,
then i followed this guide: https://www.youtube.com/watch?v=lUsMVrs1ot0

but when using this command: sudo npm -g install pm2
i get this error: sudo npm WARN optional dep failed, continuing [email protected]
but after awhile it continues and it looks ok: but then homeassistant ui wont start.
i can still use ssh.

can someone help me to get this working?

//Regards

check the homeassistant.log file in your configuration folder.