According to the Modelica specification 3.2rev2, section 9.3.1: For each non-partial connector class the number of flow variables shall be equal to the number of variables that are neither parameter, constant, input, output, stream nor flow. Basically saying that the number of flow variables should be equal to the number of potential variables. this might cause the problem in the library.
We will take a look at this and verify whether it's a library problem or due to something that is not supported in WSM yet. you.