M1chel

To answer my own question for reference to anybody might have a similar problem in the future:

the problem was in my custom theme.
after some debugging using the diagnostic tool of the plugin “healthcheck and troubleshooting” I found out switching to a base theme like twentytwenty restored the featured image panel.
I’m not sure why in my theme it worked for some time and disappeared later but the solution was to add support for featured images and thumbnails in the function.php file.

so I added this code found on stack exchange

function my_theme_setup(){
    add_theme_support('post-thumbnails');
}

add_action('after_setup_theme', 'my_theme_setup');

I have great respect for moderators helping the community and I admire the fact they spend time to help users like me.

So, I’ll avoid getting in a debate about what 10 line means or is. I’ll just thank you again for the help.

first, thank you kindly!
your help means a lot and I’m gonna try this bit of code right away ??

second, yeah the nazi thing was provocative, but this is a place to seek help and give each other a hand. erasing someone’s code from a post just because it exceeds of 1 line the general rule is a misuse of moderating power.
I didn’t have a notification so I didn’t see the action taken and my topic was as a result useless.
I understand the rule, it’s meant to avoid long pages of code cluttering the topics, but 1 line over the limit doesnt change anything.
that being said, I’m sorry if I offended someone, it was a lightheart comment not intended to cause problems. ??
I suggest however to be careful giving moderation power to people who can handle wisely the task and actually help the community.

thanks again for helping me.

sorry, I noticed now a possible solution in the wordpress “troubleshooting” section. I’ll try that.

Well no, I was wrong unfortunately. I thought I solved it because I had the problem occuring when I was using links in my headers, which I fixed as I wrote above, but today I noticed I can’t login to mysite.com/wp-admin
because I get that error.

I’ll try to find a way around, but it’s something wordpress team should really help people with. I saw many topics about this problem.

Hi, I just ran into the same problem and fortunatly I found a solution.
the error shouldn’t be related to the integration with bbpress, but it’s something more general.
here https://www.hongkiat.com/blog/wordpress-error-warning-cannot-modify-header-information/ it suggests to erase possible blank lines in the wp-config file before and after <?php ?>
In my case I did it and I still had the problem so I also used this trick https://stiern.com/tutorials/no-more-invalid-rss (which also works for invalid rss – and I had that too) which get rid of blank lines on top of <?php from everywhere, so you should be good to go after that.

It worked for me, I hope it does for you ??

I looked for a while into the problem and I couldn’t find which file was affecting the feed.
Finally I used this solution: https://stiern.com/tutorials/no-more-invalid-rss
Yesterday I tried the same thing but with the .htaccess file and I damaged something important which got me to reinstall wordpress.
I suggest you modify just the index file like described on that site.

Thanks Esmi for your time.

uhm, I edited the header.php and also my custom home.php where the only thing before the doctype was

<?php
/**
Template Name: header
 */
?>

now it’s gone but my problem is still there..
Any other advice? can you spot something else?

thank you!

Hi Esmi, sorry I didn’t know about pastebin.
Here’s my code https://wordpress.pastebin.ca/1541609 , now you can moderate my previous post if it’s possible.

the url of my site is https://designerbreak.com

Hi, I have to bring this up again coz now I’m trying to set up the subdomains of my blog and I’m experiencing problems.

I have myblog.com where I installed wordpress.
I have a subdomain mob.myblog.com which is the mobile version and it should use the same db, just a different theme.

I have eng.myblog.com e eng.mob.myblog.com which are the english version of my blog with its moble version. they will have a different table in the database because they’ll have posts in english.

I installed wordpress on the main domain and I copied the installation in the mobile subdomain with the same db prefix coz they’ll have the same posts, but when I login to mob.myblog.com/wp-admin/ I get redirected to myblog.com/wp-admin/ and I think I can’t change theme without influencing also the main domain. how I solve this?

thanks for the infos!

it didn’t worked for me. it’s basically what I also did before.
I mean, yeah it finds the page but any “include” tag of wordpress generates a fatal error.

Well, if I state the whole path to my 404 page in .htaccess file then it displays it in case of an error, but it’s like it is not related to wordpress.. there’s no header nor footer even if I put the tags.
And it has no styles coz the link to the style sheet is in the header.

If I can’t solve this I’ll probably put in the 404.php the code that I use in the header and in the footer instead of tags, but still everything dinamic that is related to wordpress won’t work.
And the worst part is that then I can’t obviously put a search form.
really annoying.

I guess I’ll do my best to deal with it.
But If someone has any suggestion is appreciated.
I’ll keep this topic up to see if we can solve the problem.

Thanks to everyone tried so far ??

yes, my page is named 404.php
and 404 is also the name I used inside as “template name”.

is this correct?