How i edit Featured Image size

why i receive this message on wordpress

Warning: call_user_func_array() expects parameter 1 to be a valid callback, function ‘modify_featured_image_size’ not found or invalid function name in /home/content/96/11866696/html/blog/wp-includes/plugin.php on line 525

before now i try edit Featured Image size at Activello: Theme Functions (functions.php)
by add

function modify_activello_featured(){
add_image_size( ‘activello-featured’, 1024, 1024, true );
}
add_action( ‘init’, ‘modify_activello_featured’, 10 );

because I read it here https://colorlibsupport.com/t/change-the-featured-image-sizecrop/

but I don’t know how i can do it

Thanks
Bellta

Hi Bellta,

I hope you are well today and thank you for your question.

The shared code is working fine on my test site so not sure why you are getting the warning message.

Could you please share me the file where you have added it and getting the warning message so that i can troubleshoot it?

Kind Regards,
Movin

Hi Movin

Thank you so much
Now warning message is lost

but I have next question
I want to know why different size and different resolution?
you can see at [email protected] and [email protected]

For [email protected] I move from blogger
but [email protected] is normal

Thanks
Bellta

.

I cannot upload photo of [email protected]

you can see at [email protected] and [email protected] ?

I want to know why different size and different resolution?

I am not sure what you meant by this so could you please describe it a bit more in detail?

Also please share me the exact site or page URL where it is displaying and not the email ids of them which you have shared.

Oh sorry

It is travel.belltastudio.com and blog.belltastudio.com

I try upload photo at Featured image and at Post space
Now I think Featured image is different

My question

  1. why photo different size and different resolution?
  2. why I have 2 photo at homepage? I must don’t put first photo at Post space?
  3. Featured image use for what?
  4. If I share article,Featured image or first photo at Post space is show?

*For blog.belltastudio.com I move from blogger
but travel.belltastudio.com is normal

And this is last article move from blogger belltastudio.blogspot.com to blog.belltastudio.com
http://blog.belltastudio.com/2016/05/why-we-should-be-used-variation-option/
All article move from blogger I must edit by add Featured image and delete first photo at Post space
I mean if no add Featured image, cannot see photo at homepage
but if add Featured image and no delete first photo at Post space, can see photo at homepage 2 photo
However,all article move from blogger I can edit it each article
but now i want to know how to use normal wordpress in the future

sorry if my english very bad

Thanks
Bellta

http://blog.belltastudio.com and http://travel.belltastudio.com/

1. why photo different size and different resolution?

Answered in your following topic.

https://colorlibsupport.com/t/why-photo-on-site-is-different-size-and-different-resolution/

2. why I have 2 photo at homepage? I must don’t put first photo at Post space?

Yes you are right you must don’t put first photo at Post space so that 2 photos won’t display on homepage.

3. Featured image use for what?

It is used to display the image on the top of the post. Find more information about this here http://www.wpbeginner.com/glossary/featured-image/

4. If I share article,Featured image or first photo at Post space is show?

Mostly the Featured image.

Thank you so much!
Bellta ^^

You are most welcome here :slight_smile: