This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
I find it very odd that a DTD declaration would point to a schema. Very odd indeed. I would expect it to point to a valid DTD. Apparently the parser agrees with me. You might consider reporting that to the people who support the product.