Drush: "Unknown engine type outputformat" module conflict I've been searching in all forums for the answer, I had a problem with drush everything i did showed this message "Unknown engine type outputformat [error]" 

I updated drush and still got that message since it took me so long to find the answer I'll post it here for other people with the problem 
its the first answer.
The solutions is one of 3 things:

1.- Update drush

2.- Clear drush cache

3.- If you have the module "module_missing_message_fixer" the best solutions is to disable the module make the changes on drush and enable it when you are done, for some reason that module stops drush from working. 

I hope this helps someone else.