wordpress refuse to install plugins through dashboard

WordPress showed many permission problems when we tried to install it on a fresh install of Unix -- Ubuntu 16.04, the first and most annoying problem is the plugins from WordPress.org will not install locally and the WordPress continue to complain of access problem and asking for ftp credentials.

So, to solve this issue the first thing to do is change the ownership of WordPress folder to the  www-data:

sudo chown -R www-data:www-data /var/www/html

and change the chmod for the WordPress folder to allow write and read for the wp-content folders


the most important step to avoid this problem is to add this option to wp-config.php

define('FS_METHOD', 'direct');

Here is a nice blog post which explain how to install WordPress the right way :

install-wordpress-ubuntu-16-04

Error: More than one instance of bitcore-lib found

this error was shown when I tried to run bitcored on linux after adding new service which was the bitcore wallet service , the problem happened after each sub module trying to run its own copy of bitcore-lib, the bitcore.node depends on version "bitcore-lib": "^v0.13.19", and the bitcore-wallet-service depends on version "bitcore-lib": "^v0.15.0". So we have to remove one of these dependencies from the package in order to solve this problem:

npm uninstall --prefix /mynode/node_modules/bitcore-wallet-service -S bitcore-lib