In scenarios such as multi-site management, virtual host deployment, automated SSL configuration, and coexistence of multiple PHP versions, the Plesk control panel is widely adopted by server administrators due to its user-friendly interface, strong extensibility, and compatibility with Linux and Windows. However, in actual deployment, many users encounter problems such as the installation process getting stuck, failure at a certain stage, incomprehensible error codes, and the installer being unable to continue. Since Plesk installation depends on numerous system packages, library files, service components, and network sources, any deviation in any of these can lead to installation failure. Understanding the meaning of common error codes and taking corresponding remedial measures can significantly reduce troubleshooting time and improve deployment success rate.

　　Among Plesk installation failure errors, Exit code 1 is the most common and general type. In most cases, Exit code 1 indicates that a system command executed by the installer failed, which may be due to reasons such as unavailable system software sources, package conflicts, insufficient disk space, missing dependency libraries, or network interruption. The most effective troubleshooting method is to read the installation log file `/var/log/plesk/install/autoinstaller3.log`, which records the specific commands that failed. For example, if the log shows a message indicating that the software source cannot be accessed, you can resolve the issue by changing the system image source.

sudo sed -i 's|http://.*archive.ubuntu.com|http://mirrors.aliyun.com|g' /etc/apt/sources.list
sudo apt update

　　For CentOS/AlmaLinux/RockyLinux users, switching to the BaseOS and AppStream sources can prevent installation failures due to official source maintenance.

　　Exit code 100 is another common error, usually indicating that the package manager encountered an unresolved dependency conflict. These problems are often caused by a minimal system installation, residual old packages, missing critical components, or the prior installation of incompatible software. For example, some users may have MariaDB or Nginx installed before installing Plesk, and different versions may cause conflicts. The solution is to remove unnecessary packages or reinstall according to the version supported by Plesk.

sudo yum remove mariadb-server nginx
sudo yum install mariadb-server-10.5

　　If the conflict originates from a critical system package, missing component issues can be resolved by enabling EPEL or PowerTools (AlmaLinux 8).

　　Another typical error is "Unable to resolve host name" or DNS-related installation failure. The Plesk installer automatically detects the server hostname; if the hostname is not in the correct format or DNS cannot resolve itself, component initialization will fail. The following are methods to check:

hostnamectl set-hostname panel.example.com
echo "1.2.3.4 panel.example.com" >> /etc/hosts

　　After configuration, restarting the network or simply rerunning the installer should resolve the issue.

　　Some users encounter a "Not enough space" error. Plesk's complete installation may exceed 5GB, including various PHP versions, mail service, database, Nginx, Apache, and other components. If the server's system disk is too small or the /var partition is insufficient, the installation process will exit directly. Common solutions include expanding the cloud server's disk, mounting a large-capacity disk separately to /var or /usr/local, or deleting unnecessary temporary files.

sudo rm -rf /var/cache/*
sudo apt autoremove

　　You can also expand the system disk online through the cloud provider's console and then perform a file system expansion.

　　For network-related installation errors, such as inability to connect to the installation source, download timeouts, and SSL certificate verification failures, these are often due to the server being unable to access the Plesk official repository or being restricted by a firewall. The installer relies on many external resources, so the network must have full access permissions. If using a domestic server, you need to ensure that ports such as 8447 and 8443 are not blocked and that the foreign source is accessible. You can test this by executing the following command:

curl https://autoinstall.plesk.com/

　　If a 403/200 response is returned, it's normal. If there's no response for a long time or an error message appears, you need to configure a proxy, switch to an international line, or access via an accelerated node.

　　Another common error when installing Plesk on Windows Server is "IIS configuration failed." This is usually related to the system not having the Web-Server role installed, missing .NET Framework, or related components not being enabled. Correct installation prerequisites include modules such as a web server, ASP.NET, ISAPI extensions, and CGI. If these are missing, you can automate the installation using PowerShell:

Install-WindowsFeature Web-Server, Web-Asp-Net45, Web-CGI, Web-ISAPI-Ext

　　Similarly, Windows systems must be kept fully updated; missing patches can cause some Plesk modules to fail to initialize.

　　In Linux environments, strict restrictions on FirewallD or iptables can also cause installation errors. For example, the installer needs access to the external network and local ports when creating system users, writing configuration ports, or initializing webmail services. If the user has configured overly strict security policies beforehand, it may directly prevent the installer from creating services. It is recommended to temporarily disable the firewall for testing.

sudo systemctl stop firewalld

　　After successful installation, restore the strategies one by one.

　　Another easily overlooked reason for installation failure is SELinux. When SELinux is in an enforcing state, the Plesk installer is prevented from writing to directories or creating services. It is recommended to temporarily set it to permissive.

sudo setenforce 0

　　And modify the permanent policy in `/etc/selinux/config`.

　　Besides various error codes, some hidden misconceptions often lead to installation failures, such as attempting to deploy Plesk on a system with an existing web control panel. Panels like cPanel, DirectAdmin, aapanel, and BT Panel will consume web services, database services, and mail systems, conflicting with Plesk and therefore cannot coexist. If other panels already exist on the server, they must be thoroughly cleaned up before reinstalling Plesk.

　　Another misconception is that the operating system version is not supported. For example, CentOS 6, Ubuntu 16.04, and Debian 8 are no longer maintained, and the latest version of Plesk is no longer supported. Running the installer on these systems will inevitably result in errors. The correct approach is to use the officially recommended system version and ensure the system is clean.

　　In a real production environment, installation failures not only waste time but may also leave residual files on the system, requiring manual cleanup. Plesk provides an automatic cleanup tool that can repair residual components in some cases.

/usr/local/psa/bin/autoinstaller --remove-everything

　　After cleaning and restarting the server, you can usually restore it to a clean state, ensuring a smooth reinstallation.

　　After understanding the various errors and repair methods mentioned above, let's look at some frequently asked questions. Some users ask if configuring the hostname is necessary to install Plesk. The answer is yes, and using the FQDN format is recommended. Some ask if it's normal for the installation to get stuck at 80%. Actually, Plesk takes a long time to initialize the database and mail system, which can be extended by a poor network connection. However, if it exceeds several hours, you may need to check the logs. Others ask if offline installation is possible. The official recommendation is not to install offline because too many component dependencies can lead to version inconsistencies. Still others ask why Windows installation fails but Linux installation succeeds. This is because the Windows environment has stricter component dependencies; any missing IIS or .NET components will cause failure.

　　Overall, Plesk panel installation failures are often not due to a single reason, but rather the result of multiple system factors combined. By accurately understanding common error codes, combined with log troubleshooting, checking the system environment, resolving dependency conflicts and network obstacles, most installation problems can be quickly fixed. Ensuring a clean system, using a supported version, and guaranteeing network integrity are key to a successful Plesk installation. With a clear troubleshooting approach, the Plesk panel installation will become more stable and reliable, providing a solid foundation for subsequent site management.