I did not respond, because according to my logs you sent me a message 5/7/16 at 1:30pm
and by the time I received it it was past the due date of the art department anyways. Submissions were due 5/9/16 but submissions close right at midnight going into 5/9/16, so you really only gave 36 hours for a response, which is cutting it close.
You were probably having issues submitting due to the size of your project. Though you stated it was less than 300kb sometimes the system has a hard time accepting submissions over 295kb at times. There really is no concrete way of telling why is accepts some and not others, so I recommend always trying to resize a graphic if it's not being accepted even though it already "fits" the size guidelines.
There is always a Art department Discussion topic set up in the Art Department Discussion area to ask any questions about any of the projects as well!