click edit for joomla!1.5 error Warning: trim()

( ! ) Warning: trim() expects parameter 1 to be string, object given in C:\Wamp\www\joomla15\libraries\joomla\html\parameter.php on line 83
Call Stack
# Time Memory Function Location
1 0.0005 701280 {main}( ) ..\index.php:0
2 0.0610 5574680 JAdministrator->dispatch( ) ..\index.php:67
3 0.0652 6272488 JComponentHelper->renderComponent( ) ..\application.php:136
4 0.0693 6420776 require_once( 'C:\Wamp\www\joomla15\administrator\components\com_science\science.php' ) ..\helper.php:162
5 0.0828 9536488 JController->execute( ) ..\science.php:125
6 0.0828 9536568 ScienceControllerGrade->display( ) ..\controller.php:236
7 0.0828 9536568 JController->display( ) ..\grade.php:70
8 0.0875 10159232 ScienceViewGradelist->display( ) ..\controller.php:310
9 0.0875 10159368 ScienceViewGradelist->display_gradenewedit( ) ..\view.html.php:51
10 0.1700 10800592 JParameter->__construct( ) ..\view.html.php:223
11 0.1700 10801976 trim ( ) ..\parameter.php:83

Not only a Warning.
I get a fatal.

I check this.

Hum...
1.5 is almost died.
Cook Self Service may not support anymore next month. Please migrate.

Should be solved now.

Thanks Admin mistakes that have already lost.

I'm sorry, I do not feel English.

I'm Thai.