I am getting a 404 on http://localhost/wp-json/wp/v2/posts route. I changed permalink type to plain. Still got the same issue.
If its useful, I am ubuntu 16.04 desktop recent upgrade from 15.10, suffered issues with php5.6 to 7.0 upgrade. Am now on php 7.0
Edit1: Tried every other permalink setting combination, no results!
You need to give permission to your wp-content folder. For the change the permission please use below command in terminal.
sudo chmod -R 755 wp-content/
After the change permission is still show 404 error then allow AllowOverride for apache, below is the step:
navigated to /etc/apache2/sites-enabled and opened 000-default
All of the AllowOverride variables were set to None, which I replaced with All.
After this change enable mod using below command:
a2enmod rewrite
And restart the apache service below is the command:
sudo service apache2 restart