Getting Fatal error repeatedly

Do you have all the WordPress files installed? First thing Id try it would be to reinstall those. That function wp() is what sets up WordPess variables I think.

which files you are asking ? wp admin or any others. I am not so technical person but i believe if i try to change wp content then i will lost all my website content. so kindly share me any specific details

One more thing i want to mention that i used EWWW image optimizer plugin yesterday but after using that plugin i deactivate and delete plugin on the same time

I would try downloading and unzipping the core WordPress files.

https://www.ads-software.com/download/

First try these couple of troubleshooting steps:
– Try manually resetting your plugins (no Dashboard access required). If that resolves the issue, reactivate each one individually until you find the cause.
– If that does not resolve the issue, access your server via SFTP or FTP, or a file manager in your hosting account’s control panel, navigate to /wp-content/themes/ and rename the directory of your currently active theme. This will force the default theme to activate and hopefully rule-out a theme-specific issue (theme functions can interfere like plugins).

If the above steps don’t help resolve the issue, then try:
– MANUALLY updating. Download WordPress again and unzip it, and use that to copy up. Access your server via SFTP or FTP, or a file manager in your hosting account’s control panel (consult your hosting provider’s documentation for specifics on these), and delete then replace your copies of everything on the server EXCEPT the wp-config.php file and the /wp-content/ directory with fresh copies from the download. This will effectively replace all of your core files without damaging your content and settings. (NOTE: do not delete the?wp-content?directory or your?wp-config.php?file). Please read the Manual Update directions first.
– Backup: If you haven’t already done, always backup everything (including your database) before doing any actions, just in case something really goes wrong. You can never have enough backups! See https://www.ads-software.com/support/article/wordpress-backups/

Hello, I tried first with theme but not worked. when i am trying to connect throught ftp i am getting error message

Status: Connecting to [2606:4700:3037::ac43:a5cb]:21…
Error: Connection timed out after 20 seconds of inactivity
Error: Could not connect to server
Status: Waiting to retry…
Status: Resolving address of contesasia.com
Status: Connecting to [2606:4700:3037::ac43:a5cb]:21…

try reviewing https://www.ads-software.com/support/article/common-wordpress-errors/#connection-timed-out

Hi, I tried to update all files through ftp. Website started. but again once i login into wordpress admin page and tried to edit website it shows same fatal error and website down.
Fatal error: Uncaught Error: Call to undefined function nocache_headers() in /home/u526093132/domains/contesasia.com/public_html/wp-admin/admin.php:36 Stack trace: #0 /home/u526093132/domains/contesasia.com/public_html/wp-admin/edit.php(10): require_once() #1 {main} thrown in /home/u526093132/domains/contesasia.com/public_html/wp-admin/admin.php on line 36

Hello, I can see your website is online now. Can you please share the way you did to fix it ?

Hello Alex I did all the steps as suggested by moderator so website started working fine. But again when i login into WordPress dashboard same error occurred so it is not resolved yet.

Hello, seems to be a hack.
I just asked a safety WP specialist who cleaned up the website.

Hello wordpress team please help me to resolve this issue. I tried to do everything you suggested. One thing i noticed that once i restore backup file and database through hosting website start working. But again when i try to login and start using wordpress admin dashboard. the website is again down and giving http 500 error. I already restored wordpress file through ftp but result are same. please help
Thanks

Hello, I am also Facing the same issue on some of my website. When I log in and do any changing from wordpress dashboard I get HTTP 500 Error.
If you please found the solution then put the solution here
I need help
Thanks

Hello, Site restored on back date but its temporary solution, when i again login into wordpress dashboard same error occur. WordPress experts are not able to provide any solution for this big issue. if you found any permanent solution please post here.
thanks

Thanks if you found please also post here