vim “modifiable” is off

Question

Trying to create a new file with nerd tree. I hit the a key to create a new file and i get the message:

E21: Cannot make changes, \'Modifiable\' is of

Answer 1

I am not familiar with NerdTree but I guess that by typing a into a nerdtree view, it is interpreted as " I want to append something in the nerdtree buffer", and that buffer is not modifiable.

You can check that answer vim and NERD Tree extension - adding a file which explains how to add a file with Nerdtree.