Dump when trying to invoke RFC function from Webchannel

Dear all,

I recently tried to invoke a RFC function from Webchannel. But I got dump like this:

Actually, the error message showed that, null object is pulling out from com.sap.wec.tc.core.backend.ConnectionFactory.getDefaultConnection().

I have no idea about this at all. Does anyone know it?

Thank you.

Best Regards,

Sam.