Error after creating new post or page

Try deactivating all plugins. If that resolves the issue, reactivate each one individually until you find the cause.

If that does not resolve the issue, try switching to the Twenty Seventeen theme to rule-out a theme-specific issue (theme functions can interfere like plugins).

thank you James for your reply.
tests with plugins I made the first step afternoticed this error. It is not plugins issue I checked.
The same version of theme I use at the same server at two more domains. And their this theme works fine and does not conflict with the same worrdpress version. So the issue with theme seams also wrong.
Do you have other advices for me please?

Please check with the Twenty Seventeen theme regardless. Just because the theme you’re currently using works on other sites does not mean that this particular copy of the theme wasn’t corrupted in some way.

If there’s no difference under the Twenty Seventeen theme, try downloading WordPress again, access your server via SFTP or FTP, or a file manager in your hosting account’s control panel, 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.

Some uploaders tend to be unreliable when overwriting files, so don’t forget to delete the original files before replacing them.

Thank you James.
I tried with the default theme and it did not helped.
I installed completly new wordpress and it started working fine.
Then after uploading my theme the error again appeared.
So it means the problem us in the theme and I will dig it with theme developers.
Thank you!