Working with Plesk results in two different errors

[InTerestedOWL]

Hello together,
I reach out to you because I have lots of problems with phusion. Especially with plesk, which runs nginx and apache.

First of all i use Plesk Obsidian 18.0.31 Update #2 , last updated at Dec 2, 2020 03:56 AM

I have configured two nodejs applications, started them and npm install works fine.
Everything seems fine in my eyes. But when I navigate on the first site, it shows me the following site.
We're sorry something went wrong.
Folllowing Informations are provided through development:

On the second page I got:

I followed this instructions for the integration of Nodejs in plesk everything seems so easy, but i think this is an issue with phusion. https://www.plesk.com/blog/product-technology/node-js-plesk-onyx/

Thanks for help