my MF (the newest version on this site) wont work. This is what i do

i start MF then YR
then i go into QM and i find i cant log on i have been told to delete my hosts files which when i delete this MF wont work untill i try it again which then when i try again it wont load properly it just stays on the same load-up screen.

PLZ COULD YOU HELP ME!

oh yeah and somtimes when it does connect it performs an illegal operation.