I’m trying to create a symbol (not a footprint) with the bitmap to component function. To do this I choose a bitmap and click on “Eeschema (.lib file)” to convert it to a symbol. This results in a .lib-file but unfortunately I can’t open it anywhere since KiCad (Symbol editor) doesnt recognize it. The same goes for Eeschema. I wasnt able to find any information about this online or in the docs, but correct me if there is something I didnt see.
I don’t think you did anything wrong. (Even though I have not used that Bitmap to Component myself).
KiCad does not search for libraries. You very likely have to manually ad your newly created library to the library table with: Kicad / Preferences / Manage Symbol Libraries