HaloMods "Classic" Read-only Archive

so i can get through the entire tut on bsp conversion but once i try to open the map in the entity BSP editor it always gives me an error about a non-negative number being required. then, when i tried opening a projectile, it gave me a bunch of broken ident messages. any tips?

The same thing happens to me, even though it used to work... I tried deleting all the tags and starting over, but that didn't work. And yes, my maps are clean. Does anyone have any ideas?