Cursor and Del keys not working in Vim

Problem

After changing some configurations in a vimrc, I noticed that the keys that move the cursor in Insert mode of Vim did not work. Even the Del key did nothing but move the cursor.

Solution

After examining the configuration I had added to my vimrc, I found that this behavior was caused by setting set noesckeys. Turns out that this setting disables cursor keys in Insert mode. I did not really need that feature, so I took out that line. This leaves the default set esckeys setting which works as expected.

Tried with: Vim 7.4 and Ubuntu 16.04