Mateus Getulio Vieira

A strong possibility here is that another plugin or maybe even your current theme is the one doing the ajax call to this file /wp-admin/admin-ajax.php.
If this is happening, changing the heartbeat configuration won’t be effective.
Could you test this scenario?

Please try to add this code to your functions.php file, and tell me how it goes:

function wptuts_heartbeat_settings( $settings ) {
    $settings['interval'] = 60; 
    return $settings;
}
add_filter( 'heartbeat_settings', 'wptuts_heartbeat_settings' );

Deleting the date stamp information from old posts, could, cause some impact on the post ordering in case your site is time-oriented.

You can try to surround it, by preventing this specific information from showing.
To do so, create a child theme and add the following css to it:

.entry-date {
  display: none;
}

Now, if you really want to remove the date, then you should do a complete backup first and use a plugin to do the job.

Are you running your Website locally or within a server?
This media upload problem could be indirectly related to this failed reinstall 4.9 version attempt.
Perhaps some problem with file/folder permissions or ftp storage limit exceeded, in case you’re running it into a server.

Every time WordPress loads it processes several files in background, this is a normal behavior.
To increase the performance you can work this out by activating the cache functionality in your site.
To do so please refer to this Codex article:

https://codex.www.ads-software.com/WordPress_Optimization/Caching

Hello Jan.
Thank you for your advising.
Coincidentally all my replies were spammed only after I edit them, so I thought it has something to do with the edition, that’s why I submitted other replies in sequence, sorry.

I think we already went through that line (js error browser check).

Apparently after updating to WordPress 4.9 the TinyMCE.js won’t load anymore. Probably because of that, the Visual Editor isn’t working.

Things we tried:
-Deactivate all plugins.
-Disable script concatenation with the command: define(‘CONCATENATE_SCRIPTS’, false); .
-Check for browser issues.
-Replace the TinyMCE directory for a fresh new one gotten directly from the WordPress Installation (doing a backup of the old folder before).

Still the problem remains.

What you’d suggest to fix this problem?

This issue is been caused by this code line in your header:

<link rel="stylesheet" type="text/css" href="style.css" media="screen">

It’s looking for a file named style.css, but referencing to the current directory.
Edit your current theme header.php file, replacing this line above for this one (or equivalent):

<link rel="stylesheet" type="text/css" href="<?php echo get_template_directory_uri();?>/style.css" media="screen">

• This reply was modified 7 years, 4 months ago by Mateus Getulio Vieira.

In this specific case you have to determine a bg color to the hidden menu when you hoover on its parent.

Try to replace this section:

#primary-menu .main-nav ul li:hover > ul {
  white-space: nowrap;
  display: block;
}

for this:

#primary-menu .main-nav ul li:hover > ul {
  white-space: nowrap;
  display: block;
  background-color: #595959;
}

• This reply was modified 7 years, 4 months ago by Mateus Getulio Vieira.
• This reply was modified 7 years, 4 months ago by Mateus Getulio Vieira.
• This reply was modified 7 years, 4 months ago by Mateus Getulio Vieira.

You can also do this change by editing the wp-config.php file, assuming you have access to the FTP files.

1-Download this file to your local machine.

2-Open this file and look for some lines like those:

define('WP_SITEURL', 'https://lascrucescoc.org');
define('WP_HOME', 'https://lascrucescoc.org');

2.1-If you find them you only have to change these two urls replacing it by https://www.lascruceschurchofchrist.org.

2.2-If you can’t find them, no problem, just add them manually in the end of the file.

define('WP_SITEURL', 'https://www.lascruceschurchofchrist.org');
define('WP_HOME', 'https://www.lascruceschurchofchrist.org');

After those changes, save the file, upload it back again to the FTP server and the problem will be gone.

Don’t forget to remove these lines when you regain access to wp-admin and setup the url by it.

• This reply was modified 7 years, 4 months ago by Mateus Getulio Vieira.

Please try to open this url putting your site address before the wp-include and tell me if you can see the js minified properly or if an error message will appear:

https://<yoursite>/wp-includes/js/tinymce/wp-tinymce.php

Most of the problems in the screen capture happened because of a failed load attempt on the TinyMCE js library.

That could’ve been caused by a plugin conflict. In that case you should deactivate all of your WordPress plugins, and if the problem is solved, you must activate them again, one by one, repeating the test in order to identify which one is causing this issue.

Other possible scenario here is that JS is running into a process limit before it reaches that point when it loads this library.

In that case you could try to fix this by adding

define(‘CONCATENATE_SCRIPTS’, false);

to your wp-config.php file just below the define(‘DB_HOST’) line.

Refer to: https://codex.www.ads-software.com/Editing_wp-config.php#Disable_Javascript_Concatenation

• This reply was modified 7 years, 4 months ago by Mateus Getulio Vieira.
• This reply was modified 7 years, 4 months ago by Mateus Getulio Vieira.
• This reply was modified 7 years, 4 months ago by Mateus Getulio Vieira.

A common problem with visual editor is an incompatibility with Adblock tool(or similar).
Have you got the Adblock plugin installed in your browser?
Try to deactivate it temporarily or add you wp-admin to the whitelist.
Please let me know if it will solve the problem or if you don’t have it installed in your browser in the first place.

• This reply was modified 7 years, 4 months ago by Mateus Getulio Vieira.

Проверьте этот урок, он покажет вам все возможности этой ошибки и все возможные решения.
https://goo.gl/oM8gtR

Please access your database through phpMyAdmin or similar and then locate the wp-options table.

In the top rows, probably 1st and 2nd, you will see the ‘siteurl’ and ‘home’ fields, check their values respectively and if they’re wrong you can correct them.

After that do the login within the url https://www.lascruceschurchofchrist.org/wp-login.php, after that you’ll be redirected to the correct wp-admin to do some final checkups in the settings related to urls, only by panel this time.

• This reply was modified 7 years, 4 months ago by Mateus Getulio Vieira.

Have you tried to login by the url: https://www.lascruceschurchofchrist.org/wp-login.php instead?
What happens then, the Website got you redirected again or do you gain access to the correct wp-admin panel?

• This reply was modified 7 years, 4 months ago by Mateus Getulio Vieira.