Yesterday I worked on the thema and i tried the CSS and JS Minify Free Plugin and I think I had problems from that moment.
I called the provider because the server blocked my ip from security reasons. "ModSecurity: Access denied whit code 403 .........."
In error_log.php now I have :
[12-Jul-2018 12:16:19 Europe/Bucharest] PHP Warning:  Error while sending QUERY packet. PID=245281 in /home/anuntugv/newweb.anunturgent.ro/oc-includes/osclass/classes/database/DBCommandClass.php on line 1011
[13-Jul-2018 11:54:56 Europe/Bucharest] PHP Fatal error:  Call to a member function numRows() on boolean in /home/anuntugv/newweb.anunturgent.ro/oc-includes/osclass/model/Admin.php on line 63

I do not know what happened but now when I post an ads the page shows that it loads the new ads but it gets stuck and after 1-2 minutes it gets back and it shows me it published it. During this time I can not work in the admin panel because it is blocking too.
I'm frustrated because I have been working for from 4 weeks to replace a website.
I'm currently working on a subdomain nonlive. I made changes to the theme and plugins and I would not want to lose them.
You can help me please.
I could give the authenticated ftp data to an email
if you could help me please

@Daniel
Try to disable all plugins.

I know but you can tell me please enabling and disabling the plugin CSS and JS Minify Free Plugin what files affect.
This plugin has affected everything I've worked on.
I deleted, my question is if there are some affected files left or by uninstal the plugin everything went back to normal.
The loading time of the pages is a bit big.
DB from cpanel is affected by this uninstall plugin.
If it remains affected DB after this restore I need to delete everything.
?

When plugin is uninstalled, it has no effect on functionality of osclass anymore.

I did tests on the server and it's not good.
The plugin in question does not work properly with thema tatiana and by activating it and deactivating it produced errors in the loading of the pages because they were read very hard. This plugin does not work with thema tatiana but with other possible goes right. I work on this theme on the rest I do not know

It was not tested against all possible themes, but based on how osclass works it is not possible to create ultimate solution now.