Crashes

When I log into my minecraft, and I looked to see if I was using 1.9.
I was, so I was playing with my mate and it kept crashing, saying things like "Unauthorised Access, Crash in the Java-network, contact Mojang for bugs!" so, here I am, I tried multiple times and It kept crashing, I even disconnected and reconnected to my Internet, checked my Internet, restarted my router and made sure that I was playing online. Please fix this problem.