command /ei doesn't work

If you do, for example /ei show and doesn't work, the first thing you should do is try to do /executableitems:ei show

• If it works now, well, the problem is another plugin is overriding the command /ei, an example of this is Essentials, so from now, you can either disable /ei on the plugin who overrides the command, or do /executableitems
  all the time you want to use a command from ExecutableItems
• And, if it didn't work, is because the plugin is not installed correctly and you should either check the Installation tutorial or the common errors on logs