I have ubuntu 14.04 EC2 instance. I have installed php 7 on it. when I execute any php command like php --version or any other. I get following error
PHP War
In php.ini under Dynamic Extensions the line extension=php_mysqli.dll was enabled.
I disabled it by adding a semi-colon at the head of the line ;extension=php_mysqli.dll.
Saved and exited php.ini. Restarted Apache.
This resolved the error for me.
Run Phpinfo()
Search for your php.ini path
search extension=php_mysqli.so
comment like this
;extension=php_mysqli.so
Just comment out all lines with .dll extensions because you are on Ubuntu. Ubuntu support .so files.