Description of the problem: Hi, I have a video stimulus changing in every repeat. Each time a different one among three is set depending on the name. I have first training trials that contain the video stimulus and then test trials start. Everything works just fine in practice trials. When the test trials start the video comes as it needs to be but just stays static like an image. It does not play. So, there is no problem with choosing the video depending on the name, importing and starting it. However the only problem is not playing the video. Also, I did everything the same in both practice and test trials. I do not know why it works in practice but not in the test part. Btw, everything work fine locally. I constructed the experiment with builder, do not know much about the coding structures behind it. Do you have any idea about the reason?