Hi,
Could you create the "Validate Instance" for your test case? I think input file is missing the mandatory filed "$Dilimeter$". If it is not mandatory then you should put "0" for minimum in schema. Can you post the test input and shema structure here?
Another reason i could think is if you select the "$Dilimeter$" as looping then you may get this kind of error. Did you set up the root propertys for "Complexity", early termination true, and so on?
I get same kind of error when the filed is missing. I am using that case as error handling since my input must have that field.
Siva