After downloading the files and unzipping them, the top-level folder has to be renamed from HelmholtzMedia-master or HelmholtzMedia-0.9.1to HelmholtzMedia, because Dymola (and possibly other tools) expect the top-level folder name to be identical to the package name as specified in the package.mo file.
After downloading the files and unzipping them, the top-level folder has to be renamed from
HelmholtzMedia-masterorHelmholtzMedia-0.9.1toHelmholtzMedia, because Dymola (and possibly other tools) expect the top-level folder name to be identical to the package name as specified in thepackage.mofile.