Created attachment 18275 [details]
Stack trace

Created attachment 18276 [details]
The DTD

Yes, the SAX handlers generation is broken when DTD file isn't located
in a package.
If you put your dtd file to src/anypackage it should work.

This is a problem in Java bridge.

Dan, please look at it.
Radime, or anyone, how can we reproduce this?

Oops, there are two problems:
one pointed by original submitter - Java bridge fails to create handler. This
seems to be fixed in current dev builds
second that the action issues misleading error if the action is invoked on a
file that is not under some source root.

To fix the second problem we need to update the wizard (add possibilty to choose
target location of generated sources). I guess such UI change is not possible
for 4.1.

Can somebody please reevaluate this problem ?

The problem with exception was fixed.

There is still a minor issue :
User can create DocumentHandler class and other java artifacts outside a
package. In this case, in java project for example, generated classes will not
be part of deliverable jar file.
Nevertheless, that is not a big issue as there is a workaround : either copy the
classes or create a secondary source root.
I've created a separate issue for this : see the issue 68968.

I suggest also an entire re-design of generated DocumentHandler.
See the issue  68969.

I am marking this issue as fixed.