to those who encounter the same problem as me
I solved it by manually add *install_directory*\OpenSim 3.2\bin\osimJavaJNI.dll into my environment parameter "Path"
Reason for doing that is I kept facing "unable to modify Path" (or sth like that), and see the warning that I originally posted.

I am new to opensim I try write script in matlab, thus I ran the "configureOpenSim.m" as admin, and it told me to restart and test it with model=org.opensim.modeling.Model(); However, it pops out "Required library failed to load. Check that the dynamic library osimJavaJNI is in your PATH java.lang.U...