I still same problem. look for my attachment. What its wrong?

Check your filename, use something link abc.jpg

I try but still same problem

just guessing, without access, since you have mb_string enabled, and you are using a good filename and filetype, i would think its a file permissions problem. back up your site. download akeeba admin tools, there is a button to fix permissions as they should be by default. this may help

I try now but still problem:(
Any idea?

Solved

dont forget the last step....put the permissions back!
www.dionysopoulos.me/blog/72-777-the-number-of-the-beast.html