Joomla! 1.6 is an awesome update by the Joomla! team to the community but looks like it’s a bit pain for some situations!
As you might already know, many templates and extensions for Joomla! version 1.5 don’t work for 1.6 without conversion and there is no support for legacy thing that we had in previous version of Joomla!
Today I tried installing a gavickpro template Corporate 2 on my joomla 1.6 installation and it gave me an error saying:
Fatal error: Class ‘JParameter’ not found in . . .
The error was there due to missing JParameter Class (obviously as it says!)
The solution to this issue is sort of simple though. Just add the following line of code on the top of the file giving error:
jimport( 'joomla.html.parameter' );
This will declare the class and the error will vanish.
Hopefully it works for you in any other related situation too!