fwoan

Remove that function from widgets.php and place it into functions.php

I believe this will help you:
https://codex.www.ads-software.com/Function_Reference/the_post_thumbnail

https://codex.www.ads-software.com/Function_Reference/add_theme_support

Support for something like widgets should be done in functions.php

Try clearing your browser’s cache and refreshing your site.

Rather, the is_single()

You can use WordPress conditional Tags ( https://codex.www.ads-software.com/Conditional_Tags ) to add code in specific circumstances.

You will porbably be interested in the is_post() conditional.

I recommend:

https://www.ads-software.com/extend/plugins/comic-sans-ftw/

https://www.ads-software.com/extend/plugins/rainbowify/

Glad to help.

This reaction is classic.

praveen_khm, I think I misunderstood your original post.

Another fix without having to edit the theme too much would be to create as many menus as your site needs and then set up a php if statement to decide if it should be shown on your site.

pseudocode:

if ( is_category( 'my-custom-category' ) ) {
    INCLUDE RELEVANT MENU
} else if ( is_category( 'my-other-custom-category' ) ) {
    INCLUDE RELEVANT MENU
}

Is this more in terms of what you were looking for
?

Great!

Deactivate the plugin that created the problem?

I suppose it is possible to copy the code you currently have in header.php and post that into custom-cat-head.php (making the edits your category requires) and instead of calling get_header() on your template you would just get_template_part() (https://codex.www.ads-software.com/Function_Reference/get_template_part) your custom header.

Oh, there’s always a way! However the creators of your theme will be your best resource for discovering how.

Lots of blogs’ layouts depend on having an image associated with a post. Otherwise it would look pretty awkward, look at gawker.com

Requiring an image is a way of making sure you never forget it and ruin the layout of your site. I have a couple of sites that depend on having an image in each post.