That sounds like a mistake in the one line of code that you are supposed to paste into the execution window in the Developer Console to run the grading routine. It should be "max_labs_Grades.score.Lab1b();" and only that. Sometimes the one from 1a is still there and maybe you paste this one in behind that? You need to make sure the execution window is totally empty and then paste in the code, "max_labs_Grades.score.Lab1b();" just like that. Note that the one line is different for each lab.
That sounds like a mistake in the one line of code that you are supposed to paste into the execution window in the Developer Console to run the grading routine. It should be "max_labs_Grades.score.Lab1b();" and only that. Sometimes the one from 1a is still there and maybe you paste this one in behind that? You need to make sure the execution window is totally empty and then paste in the code, "max_labs_Grades.score.Lab1b();" just like that. Note that the one line is different for each lab.
Let me know, ok?