Hi Afwas, can you tell me what you were doing when you got the error?

¥

Installing a plugun. It's under th plugin list.

*edit*
It's there under the list after you hit edit a plugin and it's at every plugin.

Cheers, I think I've found the problem.

Crack open /inc/_core/ui/forms/_form.class.php and make the following change ( approx 445 ) and see if it cures it

			case 'chicago':
				if( ! empty($field_params['legend_params']) )
				{
					$legend_params = $field_params['legend_params'];
					unset( $field_params['legend_params'] );
				}

¥

Tried the fix but introduced more errors:

line 445 contains:

			case 'chicago':
				// Temporary dirty hack:
				$r = '<div class="fieldset_title"><div class="fieldset_title_right"><div class="fieldset_title_bg">';

				if( $title != '' )
				{ // there is a title to display
					if( !empty( $icons ) )
					{
						$r .= '<span class="fieldset_icons">';
						foreach( $icons as $icon )
						{
							$r .= $icon;
						}
						$r .= '</span>';
					}
					$r .= $title;
				}

				$r .= "</div></div></div>\n";

				$r .= '<fieldset'.get_field_attribs_as_string($field_params).'>'."\n";

				break;

UPDATE: Got it.
I inserted the fix as compared with "case default" before the " // Temporary dirty hack:
"