WordPress will only prompt you for your FTP connection information while trying to install plugins or a WordPress update if it cannot write to /wp-content directly. Otherwise, if your web server has write access to the necessary files, it will take care of the updates and installation automatically. This method does not require you to have FTP/SFTP or SSH access, but it does require your to have specific file permissions set up on your webserver.
It will try various methods in order, and fall back on FTP if Direct and SSH methods are unavailable.
https://github.com/WordPress/WordPress/blob/4.2.2/wp-admin/includes/file.php#L912
WordPress will try to write a temporary file to your /wp-content directory. If this succeeds, it compares the ownership of the file with its own uid, and if there is a match it will allow you to use the 'direct' method of installing plugins, themes, or updates.
Now, if for some reason you do not want to rely on the automatic check for which filesystem method to use, you can define a constant, 'FS_METHOD' in your wp-config.php file, that is either 'direct', 'ssh', 'ftpext' or 'ftpsockets' and it will use that method. Keep in mind that if you set this to 'direct', but your web user (the username under which your web server runs) does not have proper write permissions, you will receive an error.
In summary, if you do not want to (or you cannot) change permissions on wp-content so your web server has write permissions, then add this to your wp-config.php file:
define('FS_METHOD', 'direct');
Permissions explained here:
The MySQL extension:
- Is not under active development
- Is officially deprecated as of PHP 5.5 (released June 2013).
- Has been removed entirely as of PHP 7.0 (released December 2015)
- This means that as of 31 Dec 2018 it does not exist in any supported version of PHP. If you are using a version of PHP which supports it, you are using a version which doesn't get security problems fixed.
- Lacks an OO interface
- Doesn't support:
- Non-blocking, asynchronous queries
- Prepared statements or parameterized queries
- Stored procedures
- Multiple Statements
- Transactions
- The "new" password authentication method (on by default in MySQL 5.6; required in 5.7)
- Any of the new functionality in MySQL 5.1 or later
Since it is deprecated, using it makes your code less future proof.
Lack of support for prepared statements is particularly important as they provide a clearer, less error-prone method of escaping and quoting external data than manually escaping it with a separate function call.
See the comparison of SQL extensions.
Best Answer
Apparently deleting few plugins solved the problem. The weird thing is that the problematic plugins were YoastSEO and Akismet and even after their reinstall i got tons of errors too.