A colleague and I are seeing a number of stack overflow errors in Oxygen 10 (XML Editor 10.3, build 2009070117). These occur when validating quite small XML files with relatively simple schemas. The only complexity present is that the schemas definitions are spread out over a number of files, perhaps a half dozen in all. Increasing the stack size via the Xss option seems to bring limited relief. My colleague had increased the stack size to 8192 and is still seeing stack overflows, generally followed by Oxygen freezing.