You are probably telling the LKB to load the wrong file. Load your grammar by selecting "Load > Complete grammar" from the LKB top menu and then specifying the file lkb/script (not matrix.tdl or esperanto.tdl) in your matrix directory.

If you are specifying the script file, and you're still getting this error, you may have a corrupted version of the file. Open the file in emacs and look to see if there are any extraneous characters (especially at the beginning).

Back to the Grammar Engineering FAQ.