Question

I’m currently developing 2 sites using WordPress and hosted by a shared host who was recommended to me by a couple different WP fanatics.

Site 1 will be a medium-high volume blog. With my shared host’s 1-click install, it came with the plugin W3 Total Cache, which by everything I read, is the best out there.

2 problems. For one, every time I upload a theme, I get the following error in admin:

Any time I try to change the settings in W3 Total Cache, I get about 15 to 20 of the following errors in admin:

Notice: get_theme is deprecated since version 3.4! Use wp_get_theme( $stylesheet ) 
instead. in /home/jpweber/public_html/wp-includes/functions.php on line 2824

Notice: get_themes is deprecated since version 3.4! Use wp_get_themes() instead. in 
/home/jpweber/public_html/wp-includes/functions.php on line 2824

And no matter what theme I install, I get the following 3 errors at the top of every page on the website:

Notice: add_custom_background is deprecated since version 3.4! Use add_theme_support( 
'custom-background', $args ) instead. in /home/jpweber/public_html/wp-includes  
/functions.php on line 2824

Notice: get_theme_data is deprecated since version 3.4! Use wp_get_theme() instead. in 
/home/jpweber/public_html/wp-includes/functions.php on line 2824

Notice: Undefined variable: output in /home/jpweber/public_html/wp-content/themes/respo
/functions/theme-actions.php on line 138

I’ve made no changes to functions.php, and I’ve downloaded fresh copies of functions.php, and I’ve checked the functions.php file to see if any of the answers on the author’s homepage applied, but I’ve came up with no answers.

UPDATE:

For reference, here are my lines 2821-2828 in functions.php:

// Allow plugin to filter the output error trigger
if ( WP_DEBUG && apply_filters( 'deprecated_function_trigger_error', true ) ) {
    if ( ! is_null($replacement) )
        trigger_error( sprintf( __('%1$s is <strong>deprecated</strong> 
      since version %2$s! Use %3$s instead.'), $function, $version, $replacement ) );
    else
        trigger_error( sprintf( __('%1$s is <strong>deprecated</strong> 
    since version %2$s with no alternative available.'), $function, $version ) );
    }
    }

And in my theme_actions.php file, this is line 138:

$output .= ' {font:'.$font_nav["style"].' '.$font_nav["size"].'px/1.5em 
    '.stripslashes($font_nav["face"]).';color:'.$font_nav["color"].'}' . "\n";

Answer 1

The notices kind of tell you what to do, they are pretty descriptive.
Either you follow up on the notices, or set your error level lower than notice, so the messages won’t show up anymore (not recommendedd though)