It is a Modelica 1.x library if it does not contain the appropriate within-clauses at the top of every Modelica file. You need to use +std=1.x to load it. But since OMEdit can only handle Modelica3-style annotations you will not see the icons or diagrams if you do.

But there must be more problems with the library - it is in such a bad shape I put it on my github-ignore list. Probably has mo-files that do not match the classname inside the file.

The github issue tracker has also been disabled for, but if you convince webmaster at modelica.org to open a development branch I could probably make the necessary changes to make the library parse.