Retrieve_conf failed, config not applied (upgrade)

Please guide to resolve following issue

exit: 255
PHP Warning: PHP Startup: Unable to load dynamic library ‘/usr/lib/php/modules/pcntl.so’ - /usr/lib/php/modules/pcntl.so: cannot open shared object file: No such file or directory in Unknown on line 0
PHP Fatal error: Cannot redeclare class ext_gosub in /var/www/html/admin/libraries/extensions.class.php on line 471

1 error(s) occurred, you should view the notification log on the dashboard or main screen to check for more details.

Asterisk (Ver. 1.6.2.10):
PHP Version 5.1.6

What are you running? There is no current version of FreePBX that supports either Asterisk 1.6.x or PHP 5.1.

Thanks for contributing. Currently I am running FreePBX version 2.10.0.
Module Administration snapshot is given below

.

What did you upgrade?

Actually previous engineer did some kind of upgrade and I have no idea what he did. Now I want to fix this issue. Currently I am unable to change/save on GUI.

Issue has been resolved after upgrading FreePBX from internet. Thanks for your support and time.