Having troubles after moving WordPress to another host, what could be causing the issue?

There are two domains involved in the transfer:
1. ocdod74.org/beta_site
2. ocdod174.ddns.net/

The process I followed was:
- Deactivated all plugins on the first hosting
- Backed up the database on the first hosting
- Copied all content via FTP from the first hosting
- Uploaded all files via FTP to the second hosting
- Edited the database by replacing ocdod74.org/beta_site with ocdod174.ddns.net
- Uploaded the edited database to the second hosting
- Edited the WP config for login password for the database on the second hosting

It seems like I've done everything correctly, but the site only opens the main page and the menu is displayed incorrectly. I can't access the admin panel, it shows an "Error".

Could you help me find a solution to this problem? I'm really struggling with this, maybe I missed something during the transfer.

Also, I forgot to mention that if I don't edit the database and simply upload it to the second hosting, the structure and menu of the page remain as on the first hosting, but still only the main page opens.

Additionally, there are numerous plugins installed on the site.

Let's troubleshoot the problem step by step.
1. Check the database: After transferring the database and replacing the URLs, ensure that you have replaced all occurrences of the old URL with the new one. Some URLs might be stored in serialized data, in which case a simple search and replace may not work. You can use a tool like "Better Search Replace" plugin or WP-CLI to ensure all instances are updated.
2. File permissions: Make sure that the file permissions are correctly set on the new hosting. Incorrect file permissions can cause issues with the functionality of the website. It's recommended to set directories to 755 and files to 644.
3. Check the .htaccess file: Sometimes the .htaccess file may need to be updated when migrating to a new hosting environment. Ensure that the .htaccess file is properly configured for the new hosting environment.
4. Troubleshoot plugins: Since there are numerous plugins installed on the site, it's possible that one or more plugins are causing conflicts. You can try disabling all plugins and then re-enabling them one by one to identify if any specific plugin is causing the issue.
5. Theme compatibility: It's also worth checking if the theme being used is compatible with the new hosting environment. Switching to a default WordPress theme temporarily can help in identifying if the issue is related to the theme.
6. Debugging: Enable WordPress debugging to see if any specific errors are being generated. This can provide more insight into the issue and help in troubleshooting.


Additionally, given the complexities of migrating a WordPress site with numerous plugins, it's also important to consider the following:

1. Clear cache: After migrating the site, clearing the cache can often resolve issues related to incorrect display of pages and menus. If you were using a caching plugin on your old hosting, make sure to clear its cache before the migration. Additionally, if you are using a caching server at the new host, ensure that it is configured correctly.

2. Check for hard-coded URLs: Sometimes, developers hard-code URLs in their theme files or custom templates. If this is the case, the URLs won't update when you migrate the site. Search through the theme files for any instances of the old URL and update them accordingly.

3. Test database connection: Ensure that the database credentials in the wp-config.php file are correct and that WordPress can connect to the database without any issues.

4. Server configuration: Verify that the new hosting environment meets the minimum requirements for running WordPress. This includes PHP version compatibility, MySQL database support, etc.

5. Verify the .htaccess file: The .htaccess file may need to be updated when moving to a new host. Check if there are any specific directives or rules that are causing conflicts with the new hosting environment.

6. Check for mixed content: If the original site used HTTPS and the new site does not, it can cause issues with mixed content warnings. Ensure that all resources are being loaded over HTTP or update the site to use HTTPS if necessary.

By meticulously reviewing each of these aspects, you should be able to narrow down the issue and resolve the troubles you're experiencing with your WordPress site after migrating to a new host.

The issue was identical when it came to the domain, and the solution was to be found in the Settings control panel. After locating the General item, the next step was to update the WordPress Address (URL) and Website Address (URL) fields with the new domain name or URL. Finally, saving the changes was necessary for the modifications to take effect.

The issue could also stem from the use of http/https - for instance, when transferring the website to a local server. If a link with https is saved in the database, but locally there is an http request, it's essential to update either the link in the database or the server settings.

In case the domain remains unchanged and there are no third-party plugins, everything should function smoothly.

However, if the domain varies, there are specialized plugins available to modify links.

Furthermore, it's advisable to adhere to standard recommendations: verify that the correct version of php is installed and that all required php modules are enabled.