I am also getting same problem with webcenter sites 188.8.131.52.0 installation but on Linux.
I have followed all steps mentioned in the installation guide as well as mentioned in this post.
But, still I am getting the same error. Not understanding what to do?
Can anyone please help me with the exact syntax that needs to be followed in setting the CLASSPATH in Linux and the changes that needs to be done in setDomainEnv.sh and startWebLogic.sh file?