I tried to start openvz VPS and it said "Container start disabled"

it can mean VPS is in "suspended" state i think

i can do this command to unsuspend it and run it

vzctl start XXX --force

this may also work:

vzctl set XXX --disable no --save
vzctl start XXX

XXX = ID of an openvz vps

so above commands worked to make VPS running again