Unexpected Error After Updating WordPress

Hello,

I worked for a client’s WordPress Site.

It was an outdated one, so I updated it. Prior to that, I made sure to have a backup ready, and deactivated all plugins.

For some unknown reason, the page just keep on loading while it was updating. Then after 5 minutes of waiting, I opened a new browser and checked if the site is still up and it was good. However, when I tried to login, I can’t use the current user and password. Good thing, the client is cooperative so I was able to retrieve a new password using the password retrieval form.

I was able to login, and installed a new theme. I also activated some of the useful plugins and deleted the unnecessary ones. Now, I wanted to install a new plugin. When I was about to search for the plugin when I noticed the following messages:

An unexpected error occurred. Something may be wrong with www.ads-software.com or this server’s configuration. If you continue to have problems, please try the support forums.

I tried to disregard, it but when I click on “Search Plugins” button, the same message appeared in a much prominent page.

Can someone tell me what’s wrong?

The client’s hosting is j3web and it uses Helm panel instead of the well-known cPanel.