Symptoms
- Domain
example.com
 shows one of the following errors:Uncaught Error: Call to undefined function mssql_query()
OR
Uncaught Error: Call to undefined function mssql_connect()
- The domain in question is using PHP version 7.0 or higher:
MYSQL_LIN: #Â plesk db “select d.name,h.php_handler_id from domains d join hosting h on h.dom_id=d.id” | grep example.com
+———————————————+———————+
| name          | php_handler_id   |
+———————————————+———————+
| example.com       | plesk-php70-fastcgi |
Cause
Webspace example.com calls the mssql_query()
 or mssql_connect()
function, which was completely removed in PHP 7.0.0.
Resolution
Install the sqlsrv
extension for PHP 7.0 as described in the following article:Â How to install mssql or sqlsrv extensions for PHP?
Note: This extension was not officially tested with Plesk and it is not officially supported. Perform all operations at your own risk.