Currently i have a server running Ubuntu 14.04 on a LEMP stack, i was trying to enable UFW following this tutorial.

But after i run ** sudo ufw allow ssh**

I'm getting the following error:
ERROR: initcaps
[Errno 2] modprobe: ERROR: ../libkmod/libkmod.c:556 kmodsearchmoddep() could not open moddep file '/lib/modules/3.13.0-36-generic/modules.dep.bin'
ip6tables v1.4.21: can't initialize ip6tables table `filter': Table does not exist (do you need to insmod?)
Perhaps ip6tables or your kernel needs to be upgraded.

Any ideas?