problems after upgrading to 4.0?

hi there, i have been having maaaaaaany problems since i upgraded to wordpress 4, the first thing sometimes when i am on the wp-admin it shows the source code instead of the graphics, second thing i ahve been trying to upload some media but each file convert to more than a thousand file!!!

i have checked for ddos attacks and viruses and all what can be made and nothing is there!

any one have any idea?!

and yea it started the day that i upgraded to v4