how to how to hotspot wifi in ubuntu linux
  go to System settings > Network > Wireless > Use as hotspot  > Configure (or 'Edit connections' under your connections > Edit  the hotspot connection)  Switch to IPv6 Settings tab > Set Method to 'Ignore' and confirm/save  in terminal (Ctrl + Alt + T) run the following command to kill all dnsmasq processes: sudo killall dnsmasq  go to System settings > Network > Wireless > Use as hotspot   use these steps. It should work