You need an account at the CDS department. Dymola will be installed on some of their Linux-machines (they will be announced shortly). You have to use the command dymola5 to get the new user interface that I generated. The simple exercises can be done using the demo-version, that can be downloaded from Dyasim
There are similar models, even with the same name, for different physical contexts. Dampers for linear forces will give such an error when they are connected to rotational elements.