PHP Missing JSON Extension | Possible Mis-configo on ubuntu

I used VirtualMin to back up a site from a CentOS6.2 server to a new Ubuntu 14.04 with a later version of apache.

I’m trying to get PHPMyadmin working on this site but I get this error:

phpMyAdmin - Error

The json extension is missing. Please check your PHP configuration.

I did the usual apt-get install phpfmp… and the install ran as expected and loaded a few libraries all of which appear here now:

root@shiv:/usr/lib/php5/20121212# ls -al
total 704
drwxr-xr-x 2 root root 4096 May 22 19:22 .
drwxr-xr-x 4 root root 4096 May 23 15:19 …
-rw-r–r-- 1 root root 109968 Apr 17 04:58
-rw-r–r-- 1 root root 68608 Feb 18 2014

I restarted Apache… but still get the error…

Examining carefully the php.ini for this particular domain I see:

extension_dir = /usr/lib64/php/modules

but this directory is empty on this Ubuntu distro.

on some forums addressing this issue they say:

edit the php.ini file in /etc/php5/apache2/php.ini
add the new location of the file in dynamic extension section:

so I wonder if the problem is that the back up and restore has brought over a bogus php.ini for this site?

I did not edit anything yet as I don’t want to break the server… but the files are all installed now. I just have to figure out how to initialize them and make sure this domain finds them…

Any advice will be appreciated.