Contacted my host (1and1.com) They replied:
"Please be informed that PHP version supported in the server was already upgraded to 5.4. However, the /effort2 folder in your webspace is still running PHP 5.2. Please edit the .htaccess file found in /effort2 directory and insert the script below on the very first line to parse PHP to 5.4 and to fix the error displaying in your website.
AddHandler x-mapp-php6 .php"
I did that and it fixed the problem. It was another day before I discovered it had caused a different problem. When I tried to log in to the dashboard, I got:
*Fatal error*: Call-time pass-by-reference has been removed in
on line *137
Called them back and they said they do not provide support for .htaccess issues. (!). But they did point out that the error was pointing to a different plugin.
I deactivated add-from-server and now can access dashboard and still don't have the preg-replace error showing.
Just in case this might help someone else. Now I need to explain this to the add-from-server developer.