I see two things when I look at the input file you uploaded. First, you are using quotation marks around the x in column I of the file. Exactly what are you trying to accomplish with that notation? Secondly, you are missing any kind of entry in the Stim column that is column O of your file. You need to put at least some kind of valid entry there. If you wanted to display a blank screen, for example, simply put a ~ in the cells of column O.