Plutonium

For some reason this mainly seems to be happening on the last mission on coop. The first time it happened I had been in the coop server since the Hard Landing mission, and once me and my team made it to the last mission, I got booted with a server disconnected error. Each time I tried to reconnect it kept giving me a timed out error. I even restarted the game and it still kept giving me the same error. Then it happened again today. I had been in the server since the Their People, Their Blood mission this time and it gave me the same error once me and my team made it to the last mission. I tried restarting the game and it didn't work