Crash in custom plugin

I added the following to my dissector to make use of wireshark's xml dissector:

static dissector_handle_t xml_handle;
xml_handle = find_dissector("xml");
call_dissector_only(xml_handle, xml_tvb, pinfo, tree, NULL);

But now I am getting the following error whenever I capture a packet that makes the code execute:

"This application has requested the Runtime to terminate it in an unusal way."