I am having a strange error in stencyl.

Hi, Everything was going good. I changed the pre-loader background and because of that i am getting this strange error. I am unable to see the game now and gives this error every time. Please help!

What i did now. I exported the whole game and then re-imported it with a new name and it worked but please let me know and other people about this issue. This error just taken a breath out of me