Installation Guide - Troubleshoot Your Installation


This documentation describes additional steps to use if you install cPanel & WHM with this guide, but still experience problems.


Security issues


When you log in, you may see the message: There is a problem with this website's security certificate.


All new cPanel & WHM servers install a self-signed certificate. Most modern browsers no longer recognize self-signed certificates as secure and will display a warning.


To resolve this issue, replace the server’s self-signed certificate with a certificate that you purchase from WHM’s Purchase and Install an SSL Certificate interface (WHM » Home » SSL/TLS » Purchase and Install an SSL Certificate).

If your hosting provider allows it, your server will attempt to install a free hostname certificate from WebPros International, LLC during the installation process. For more information, read the Free cPanel-signed certificate section of the Purchase and Install an SSL Certificate documentation.

License errors


You see license errors during or after the installation process (for example, a License File Expired message).

  • Your license may be expired or improperly configured.
  • Your system may not connect properly to the WebPros International, LLC license servers.
  • Your server may use an invalid hostname.
  • Your server may use an incorrect date and time.

To troubleshoot this issue, perform the steps in our How to Fix License File Errors documentation.

Perl installation errors


You see the following error message during the installation process:

Fatal! Perl must be installed before proceeding!

Perl must exist on your server before the installation script for cPanel & WHM can run successfully. If Perl does not exist during installation, the cPanel & WHM installer attempts to install Perl as follows:

If the installation does not succeed, the system displays this error message.

  • We strongly recommend that you allow your operating system’s distribution to control the system Perl installation. Do not customize this Perl installation.

  • For more information about Perl on your server, and which versions of Perl ship with specific operating systems, read our Guide to Perl in cPanel & WHM documentation. cPanel & WHM servers use multiple Perl environments.

  • On AlmaLinux OS, CentOS, or CloudLinux™ servers, make certain that yum functions properly. To attempt to install Perl again on any of these operating systems, run the following command:

    yum install perl

  • On Ubuntu servers, make sure that apt functions properly. To attempt to install Perl again on the Ubuntu operating system, run the following command:

    apt -y install perl-base

High CPU load on Hyper-V


The server reports a high CPU load, and Hyper-V’s Dynamic Memory option is enabled.


This problem is due to an issue with sleep interruptibility in Hyper-V.


For more information and a patch to fix the issue, visit the LKML website.

Package installation failures


One or more RPMs or .deb packages fail during installation.


There are several reasons why your operating system’s package installations may fail.


For steps to fix this issue with RPMs, read our RPM Installation Failures documentation.

We currently do not have documentation for how to fix .deb package installation failures when installing cPanel & WHM on Ubuntu.

Resolver errors


You see the following warning during the installation process:

The system DNS resolvers went missing when cPanel adjusted the hostname.
  • Your hostname did not resolve during the installation process and the system replaced it with an automatically-issued hostname.
  • Your system’s DNS resolvers disappeared, and the installation process attempted to fix the issue.

We attempt to detect when your system’s DNS resolvers disappear and correct the issue.

On systems that run AlmaLinux 9, Rocky Linux™ 9, or CloudLinux 9, the installation process performs the following actions:

  • Writes the following contents to the /etc/NetworkManager/conf.d/99-cpanel.conf file, which configures the NetworkManager service to never overwrite the /etc/resolv.conf file:
    dns = none
  • Reloads the NetworkManager service.

On all systems, the installation restores the contents of the previous /etc/resolv.conf file before it checks the hostname.


If your resolvers are not correct, you can use WHM’s Resolver Configuration interface (Home » WHM » Networking Setup » Resolver Configuration) to add and update the resolvers on your server.

You can update your server’s hostname in WHM’s Change Hostname interface (Home » WHM » Networking Setup » Change Hostname).

Hostname issues


A cloud-hosted server does not retain the hostname setting.


The dhclient script that the cloud hosting provider uses may interfere with cPanel & WHM’s hostname configuration script.


For steps to fix this issue, read our Cloud-Hosted Hostname Solution documentation.

Installation issues with ESET


Some servers reported installation issues with ESET® File Security,


This problem was due to conflicts between ESET and cPanel & WHM in version 88 and earlier.


ESET is a third-party product and we do not provide support for third-party products.