when connecting a ender io gas conduit to the Electrolytic Separator crashed the server but not the client here is the crash report http://pastebin.com/P6neYebz

Can confirm. Placing an enderIO gas conduit on Chemical Infusers causes a crash as well, not just Electrolytic Separator (And likely all other Mek gas machinery?)

Looks like an issue on EnderIO's end though unless I'm mistaken. It seems to be their function that's throwing the error.

EnderIO's end