Errors like this are logged. Check the error log on your server. If you can’t find the log, please contact your host.
Meantime, enable wp_debug and wp_debug_log and after an error, look at wp-content/debug.log to see if anything gets logged there. https://wordpress.org/support/article/debugging-in-wordpress/
You can also try this: Please attempt to disable all plugins, and use one of the default (Twenty*) themes. If the problem goes away, enable them one by one to identify the source of your troubles.
If you cannot access wp-admin, there are other ways to deactivate plugins.
AT this time, I wouldn’t go to PHP 8. There are still missing components (e.g., pecl-imagik).
Thank you for your fast responce.
This is debugging I got on screen:
Fatal error: Allowed memory size of 41943040 bytes exhausted (tried to allocate 32768 bytes) in /home/adp1group/public_html/wp/wp-content/plugins/woocommerce/includes/class-wc-ajax.php on line 1555
Fatal error: Allowed memory size of 41943040 bytes exhausted (tried to allocate 24576 bytes) in /home/adp1group/public_html/wp/wp-includes/pomo/streams.php on line 173
It looks Woocommerce cause problem with ajax
yep, after I disable woocommerce site works, BUT Woocommerce is that main plugin I need for web shop.
Well, I’m stupid!
I mistakenly replaced the values for memory_limit and post_max_size. Of course, as soon as I increase the memory_limit site works with woocommerce. Oh her. I apologize for my mistake and for wasting your time.
No problem. No time wasted at all. And you learned something today, so take the rest of the day off.