bug fix core
bug fix core

erikasf/jsPsych,msrresearch/jsPsych,jspsych/jsPsych,vergenzt/jsPsych,shamrt/jsPsych,wolfgangwalther/jsPsych,Scienthusiast/jsPsych,jspsych/jsPsych,jspsych/jsPsych,adrianoesch/jsPsych,shamrt/jsPsych,erikasf/jsPsych,andyh616/jsPsych,adrianoesch/jsPsych,wolfgangwalther/jsPsych,andyh616/jsPsych,vergenzt/jsPsych,Scienthusiast/jsPsych,jodeleeuw/jsPsych,jspsych/jsPsych