Product Version = NetBeans IDE 6.9.1 (Build 201007282301)
Operating System = Windows XP version 5.1 running on x86
Java; VM; Vendor = 1.6.0_24
Runtime = Java HotSpot(TM) Client VM 19.1-b02
This looks to me like a duplicate of issue 198056 although I'm not sure how you have ended up in this state. "-schema" attribute was introduced in NB 7.0. Have you opened your project in NB 7.0? If you keep using NB 7.0 with Patch1 or NB 7.0.1 then everything should work. For NB 6.9 you could try to shut down the IDE and rename <your-project>/nbproject/build-impl.xml and restart IDE - it should for recreation of build-impl.xml to state in NB 6.9 which is not using -schema attribute. Let me know how it goes. Thx.
*** This bug has been marked as a duplicate of bug 198056 ***