I tried to upgrade my PHP 5.2 to PHP 5.3 but when I did I started getting errors from Multisite - this is one of them, I receive this when trying to open the plugin inside the adminsection so I can add the domains I want to share.

PHP Notice: Undefined property: JElementDomains::$element in C:\Inetpub\vhosts\buysellorfind.com\httpdocs\tst\plugins\system\multisites_ssidomains\domains.php on line 87


In the domains I have already shared, I am not able to see the sites at all after I log in and it lists the sites shared, with the error afterwards that the index is not defined...

Is there a setting I am missing in PHP.ini, the ini files look pretty much the same.

First the message is a PHP Notice and not an error.
Second, if this message appears on the screen, this means that when you have upgrade your PHP, you also requested to display all the error upon screen. In product, the error should be hidden to avoid reveal information to hackers.

Can you mention the Joomla version for which you have this notice message ?
I think you are using the Joomla 1.5.

This notice message is not critical.
The line 87 just make reference to a field that is not filled.
I will update this line to avoid the "notice" message reported in a next release of the SSI Domain