So you're trying to make a trainer for HiddenProject?
Haha I don't think the creators would be too happy about that, but sure. xD
From looking at the error, It looks like some permission/security issue you've got there.
I tried making a trainer for HiddenProject a while ago and I never got that error, but I never finished it because I got lazy and decided
there was no point in making a trainer for a private server xD
I'm not sure how you would go about fixing this problem.
But, make sure you have a line of code like
"System.security.allowDomain("http://infinityarts.co/");" or something similar :P
Also, it could be a problem locally on your computer, so make sure your flash settings are configured correctly.
Make sure you have all necessary locations set to trusted.
More Info:
Adobe - Flash Player : Settings Manager - Global Security Settings panel