Oxygen is overflowing the stack trying to validate one of my XML files against its schema. However, if I modify this file: C:\Program Files\Oxygen XML Editor 9\oxygen.vmoptions from this: -Xmx700m to this: -Xmx700m -Xss1024k Oxygen fails to start. I select it from the Start Menu and get this message: Error The JVM could not be started. The main method may have thrown an exception. If I delete the Xss option again it works. I've tried values of 512k, 512 and 1024k. This is on XP SP2 with Oxygen build 2007121417 Should the options be on multiple lines? Any help on how I can increase the stack size? FWIW, the failure seems to be on this attribute: <xs:attribute name="values"> <xs:simpleType><xs:restriction base="xs:string"> <xs:pattern value="(-?(\d+|\d*\.\d+)(,-?(\d+|\d*\.\d+))?;)*-?(\d+|\d*\.\d+)(,-?(\d+|\d*\.\d+))?"></xs:pattern> </xs:restriction></xs:simpleType> </xs:attribute> with this value: values="0.109,0.109;0.114,0.114;0.129,0.129;0.154,0.154;0.187,0.187;0.226,0.226;0.271,0.271;0.319,0.319;0.368,0.368;0.416,0.416;0.461,0.461;0.500,0.500;0.533,0.533;0.558,0.558;0.573,0.573;0.578,0.578;0.573,0.573;0.558,0.558;0.533,0.533;0.500,0.500;0.461,0.461;0.416,0.416;0.368,0.368;0.319,0.319;0.271,0.271;0.226,0.226;0.187,0.187;0.154,0.154;0.129,0.129;0.114,0.114;0.109,0.109;0.114,0.114;0.129,0.129;0.154,0.154;0.187,0.187;0.226,0.226;0.271,0.271;0.319,0.319;0.368,0.368;0.416,0.416;0.461,0.461;0.500,0.500;0.533,0.533;0.558,0.558;0.573,0.573;0.578,0.578;0.573,0.573;0.558,0.558;0.533,0.533;0.500,0.500;0.461,0.461;0.416,0.416;0.368,0.368;0.319,0.319;0.271,0.271;0.226,0.226;0.187,0.187;0.154,0.154;0.129,0.129;0.114,0.114;0.109,0.109;0.114,0.114;0.129,0.129;0.154,0.154;0.187,0.187;0.226,0.226;0.271,0.271;0.319,0.319;0.368,0.368;0.416,0.416;0.461,0.461;0.500,0.500;0.533,0.533;0.558,0.558;0.573,0.573;0.578,0.578;0.573,0.573;0.558,0.558;0.533,0.533;0.500,0.500;0.461,0.461;0.416,0.416;0.368,0.368;0.319,0.319;0.271,0.271;0.226,0.226;0.187,0.187;0.154,0.154;0.129,0.129;0.114,0.114;0.109,0.109;0.114,0.114;0.129,0.129;0.154,0.154;0.187,0.187;0.226,0.226;0.271,0.271;0.319,0.319;0.368,0.368;0.416,0.416;0.461,0.461;0.500,0.500;0.533,0.533;0.558,0.558;0.573,0.573;0.578,0.578;0.573,0.573;0.558,0.558;0.533,0.533;0.500,0.500;0.461,0.461;0.416,0.416;0.368,0.368;0.319,0.319;0.271,0.271;0.226,0.226;0.187,0.187;0.154,0.154;0.129,0.129;0.114,0.114;0.109,0.109;0.114,0.114;0.129,0.129;0.154,0.154;0.187,0.187;0.226,0.226;0.271,0.271;0.319,0.319;0.368,0.368;0.416,0.416;0.461,0.461;0.500,0.500;0.533,0.533;0.558,0.558;0.573,0.573;0.578,0.578;0.573,0.573;0.558,0.558;0.533,0.533;0.500,0.500;0.461,0.461;0.416,0.416;0.368,0.368;0.319,0.319;0.271,0.271;0.226,0.226;0.187,0.187;0.154,0.154;0.129,0.129;0.114,0.114;0.109,0.109" Is there any way to turn off backtracking for the regexp, which presumably would help here?