Subject: Problem running UIMA Ruta ExampleProject

Hi all,

I am trying out UIMA Ruta and having hard times figuring out how to run
ExampleProject. I am not a Java guy and at this point feel already
frustrated with abundant documentation.

My steps so far have been to:

1) install Eclipse Version: 2019-03 (4.11.0) on Debian Linux
2) install UIMA Ruta plugin from (via elipse menu
[Install New Software])
3) download und unpack source distribution of UIMA Ruta 2.7.0 (found at
4) start eclipse and import ExampleProject from the distribution downloaded
in step 3)
5) in Eclipse, go to ExampleProject/input/Example1.txt, right click, select
[Debug As], then in Debug Configurations there is already Main.ruta, i
simply choose it and click Debug button.

As a result, I get an error Source not found. This is the stack:

org.apache.uima.ruta.ide.launching.RutaLauncher at localhost:43931

Could you please help me understand what is wrong? What am I missing?
Please bare with a non-Java guy if I am asking a really basic/stupid/etc

Thank you in advance