Activate SEF URLs on Joomla 2.5

Closed - This job posting has been filled and work has been completed.

Job Description

We need the SEF URLs to be activated on our site, but when we flip the switch on the Global Configuration, we get an error. We don't know why this is happening, so we need someone with PHP and Joomla experience to get this working for us. For example want our URLS to read:

instead of: