Florian,
I am confused, I re-installed ABAP in Eclipse - Appv from software corner
In addition I installed ABAP Development tools
The ABAP development tools is a separate application that is not part of HANA Studio
--> The perspective ABAP exists in the ADT tool, but not in HANA Studio
--> I still can't figure out which SAP system HANA Studio is using
More documentation reading
Thanks