The component appears to be doing what it's supposed to do, but persists in throwing up this dialog.
I've been reading some about this "error code". 200 appears to be a return code in Ajax which means success, but if the return isn't set up properly it can be interpreted as an error. Is it possible that this is the case, that something in the return isn't formatted correctly?
I still have the package of an older version of VM excel like (2.0.95), which did not have this problem. As a test I uninstalled the new one(2.1.19) and installed the old one(2.0.95), and the problem goes away.