So, if anybody will meet this issue, I’ve the solution.
The problem comes from the memory limit:

Fatal error: Allowed memory size of 104857600 bytes exhausted (tried to allocate 92 bytes) in /var/www/web2045/html/xyz/wp-content/plugins/revslider/includes/slide.class.php on line 53

There is a way to increase the memory limit:
https://docs.woocommerce.com/document/increasing-the-wordpress-memory-limit/

But you should contact your host in order to get information about the max memory limit on your server…

It’s kinda memory problem. Line from log: Fatal error: Allowed memory size of 268435456 bytes exhausted (tried to allocate 32 bytes) in – directory changes. Problem dissapears when woocommerce plugin is disabled. I have 3k products. Does it really require that much of memory? In dashboard I see just 3% memory usage.

settings:
limit set in php – memory_limit = 3584M;
limit set in wp-config – WP_MEMORY_LIMIT’, ‘2048M’
‘WP_MAX_MEMORY_LIMIT’ , ‘3584M’

Hello again,

I have explain to my provider your indication and they said me that I have to ask you about how to increase this memory. They put in my root folder an archive (php.ini) and said me ask you how to modify it. This is the fatal error thats appear in my screen.

Fatal error: Allowed memory size of 62914560 bytes exhausted (tried to allocate 309717 bytes) in /homepages/4/d536887537/htdocs/clickandbuilds/WordPress/MyCMS2/wp-content/themes/enfold/css/dynamic-css.php on line 820

Thanks a lof for your help

I went to my host, presented the problem. They found the answer in one of your forums an fixed the problem. Now I’m having another problem and I don’t know if it because of the “fix” they applied or if it is something new.

The new issue is that when I am in WP, using the Avia advanced editor, when I go to “publish,” sometimes it doesn’t save and just gives me an error like this:
Fatal error: Allowed memory size of 268435456 bytes exhausted (tried to allocate 14 bytes) in /home/magnific/public_html/wp-includes/wp-db.php on line 1822. Sometimes if I refresh that page with the error, it will give me the dashboard again.
Sometimes it saves, sometimes it won’t, but it will dump me back on the “pages” page or the “posts” page and not back on the page I’ve been editing.

Below are all the details from my correspondence with my web hosting service:
ME:
Some of my blog posts are not showing up on http://www.magnificentu.com. I’ve been in contact with the designer of the theme I’m using for wordpress … because I thought that was the problem. This is the response they sent:
“We get this error in the console when we visited one of the posts:
Failed to load resource: the server responded with a status of 500 (Internal Server Error) http://www.magnificentu.com/all-spiritual-paths-lead-to-love/
You should contact your hosting provider for more info regarding this issue.”

THEM:
Unfortunately I am not able to reproduce the issue from my side at this point. Mentioned link is opening properly, as well as other links I’ve checked on your website.

Admin area dashboard is loading with no problems as well:
http://www.magnificentu.com/wp-login.php

In order for us to proceed with the investigation, please provide the exact instructions to follow in order to reproduce the problem from our side. We are looking forward to hearing from you in the nearest time.

ME:
When I click on the blog, I see the various posts.

However, when I click on the first blog post, it does not render. It
doesn’t even put up the side bar.

It is only doing this with some of the posts, not all of them. I thought
this might be a theme issue, so I contacted the theme developer. It is
Enfold for wordpress. Anyway, the message I previously sent is what they
said to me.

I had given them login information for my wordpress dashboard so they could
try to adjust things in the theme. They have changed code for me previously
and fixed things with no problem. They got the server issue.

Let me know if you need the login info for wordpress.

THEM:
I have looked into the issue with http://www.magnificentu.com/all-spiritual-paths-lead-to-love/ post and after I have enabled WP_DEBUG at wp-config.php file, I have found the following error there:

Fatal error: Call to undefined function mb_strimwidth() in /home/magnific/public_html/wp-content/themes/enfold/framework/php/function-set-avia-backend.php on line 663

According to the recommendations at https://kriesi.at/support/topic/fatal-error-in-function-set-avia-backend-php/ I have enabled Mbstrings on the server and it resolved the issue. Could you recheck it from your side and let me know if any further assistance required on this matter?

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
END OF CONVERSATION

That change did in fact fix the issue of the blog posts not showing up.
However, now I have this new problem that I mentioned at the top of this comment.
I have already supplied my log in information in the first post of this thread.

THANKS SO MUCH FOR LOOKING INTO THIS.

Hi Vinay,
thank you for the feedback. First of all i change the Memory Limit in the file wp-config.php

 * @package WordPress
 */
define('WP_MEMORY_LIMIT', '256M');

I download the XML Files and tried the following:

1. In WordPress –> Tools –> Data import –> WordPress (I must install this Plugin to import the XML File?) I Install the plugin and import the XML File.

On the Top of WordPress i receive the following error message
"P_Import::bump_request_timeout() should be compatible with WP_Importer::bump_request_timeout($val) in /var/www/web1301/html/wordpress/wp-content/plugins/wordpress-importer/wordpress-importer.php on line 38

after importing the XML File i nearly finished and then i receive the following message

Warning: Cannot set max_execution_time above master value of 30 (tried to set unlimited) in /var/www/web1301/html/wordpress/wp-content/plugins/wordpress-importer/wordpress-importer.php on line 91
Import von product_type external fehlgeschlagen

Fatal error: Allowed memory size of 33554432 bytes exhausted (tried to allocate 217088 bytes) in /var/www/web1301/html/wordpress/wp-includes/class-wp-http-curl.php on line 343

Therefore the way to import the demo Files didn’t function.

Afterwards I try the second way in WordPress through the enfold menue –> Import Demo “Small Business -Flat Demo” and i receive the following message in the POPup

Importing didnt work! 
You might want to try reloading the page and then try again

I restart and clean the cookies more than 3 times and i try different browsers and different Demos.

It would be great if you can help me to find a way out from this labyrinth :)

Thanks in advance.
eekinci

Nevermind – figured it out by loading the default 2015 theme. It was a php memory error:

Fatal error: Allowed memory size of 134217728 bytes exhausted

But I couldn’t see this in the Enfold theme for some reason. Resolved it by increasing the php memory limit in .htaccess

ok another thing that i think is connected – i am going onto the customize section and it comes up with
Fatal error: Allowed memory size of 41943040 bytes exhausted (tried to allocate 72 bytes) in /home/goldeno/public_html/testsite/wp-includes/wp-db.php on line 2346