GB> In any case, to increase the stack memory you need another switch GB> because both -Xmx and -Xms are related with the heap memory GB> setting the maximum and the start amount, respectively. To set GB> the stack memory you need -Xss, for instance -Xss1024k sets the GB> stack to one megabyte. SR> Yes, on Mac computers the schema cannot be validated with the SR> default stack size due to a StackOverflowError. With one megabyte SR> for the stack, that is -Xss1m the validation is successful. Whoo-hoo! Thank you, gentlemen. Setting -Xss worked. (I think I went straight to 2M.) My apologies for not getting back to you sooner, but this was a real in-the-nick-of-time operation, and then I've been on a plane, etc. Now, for my education: where in the documentation should I have looked to find that information? It's pretty important, and so should be pretty obvious. (Best would be to have it in the stack overflow message itself, but I presume that's coming from Java, and you don't have control over it.)