Hi Ivan,
I installed knime with Schrödinger packages. I am trying to install KNIME Community Extensions - Cheminformatics in my laptop. Note: I am not using knime server.
just to double check that you have required license to run Schrodinger nodes? (See here.)
Also what extension are you trying to install from KNIME Community Extensions - Cheminformatics group? Or you are trying to install all extensions from this group? If so wouldn’t suggest that approach rather install one by one or at least in smaller groups. That way if something goes wrong you can easier pinpoint the problem.