I'm exploring an open-source Modelica library available on GitHub. Within this library, there's a "Media" folder containing various mediums such as air, refrigerants, etc. However, I'm specifically interested in utilizing the refrigerant folder and not the entire library for any other functionality.
My approach was to copy the refrigerant folder to another location and attempt to open it in Dymola. However, I encountered an error message preventing successful execution. The error message is as follows: 
How to effectively isolate and utilize just the refrigerant package from this Modelica library in Dymola?
I think your problem is that you copy some files which are part of a larger library in the filesystem. You can read up in
withinin Modelica.My suggestion is that you open the entire downloaded library in Dymola, then you right-click on the media library you want to copy and select
New>Duplicate Class. That will create a clean copy.