Eclipse (beginner question)

For several years, I tried setting up openhab and doing everything with my text editor, because Eclipse seemed far too complex at first sight. Now, I think I need eclipse to go a step further. So I try once again, this time seriously.

I followed the instructions, but after I tried to include a binding (I first tried with miele, but then I set astro as in the instruction) the following error appeared:

I don’t know how to handle this error message. Any idea? Thanks.

Seems that you are using a not recommended Java version.

Which is currently still JAVA 8.

Hm. The exception can only happen on java9+ that’s true. But openHAB is java 11 compatible since a while now.

Thank you all for the hint with Java 8. I changed now the setting in Run Configurations to Java 1.8.
However, now if I re-run OSGi another message appears:

Launch configuration app.bndrun references non-existing project launch.

In another forum someone wrote that the Project Properties / Run/Debug Settings have to be changed, but in my case, that list is empty - no launch configurations are set and I can’t create a new one.