I am using VPL for grading tests. Doing tests directly based on the VPL works perfekt: evaluation of the code on the evaluate.cases file works as espected. But as soon as I am trying to grade the tests based on the Moodle Plugin vpl_question, I get the error: "An error occured during question grading (no grade obtained)".
I tried to debug this (debug level 8 on the jail server), which shows me that the files are uploaded as expected, the output of the test result is written into the log entry also. But it seems that this result is not transferred back to the moodle server correctly.
I get the same error when I activate the checkbox "Validate" inside the question activity, as soon as I try to save the question.
Can you please help me in solving this problem?