Step-by-step help for your hosting

• Capture and analyse network traffic with tcpdump

  Use tcpdump on a Linux server to see which packets arrive, filter by host, port and protocol, save captures for Wireshark and debug connection problems.

  AdvancedLinux VPS3 min read

• Fix file upload size errors on cPanel (upload_max_filesize, 413)

  Fix 'file exceeds upload_max_filesize', 413 Request Entity Too Large and failed uploads on cPanel by raising PHP limits correctly, or using FTP for very large files.

  BeginnercPanel hosting2 min read

• Account suspended by MdmHost for abuse or resource use: what to do

  Why MdmHost may suspend a reseller customer's account (spam, malware, resource abuse, policy), how to find the reason, fix the cause and get the account unsuspended.

  BeginnerReseller hosting2 min read

• Domain not resolving? Troubleshoot DNS step by step

  Fix DNS_PROBE_FINISHED_NXDOMAIN and "server IP address could not be found" by checking registration, nameservers, A records, propagation and local DNS cache.

  BeginnerAny domain2 min read

• Can't log in to cPanel or WHM? Fixes for every common cause

  Get back into cPanel or WHM when the login fails: wrong URL or port, password resets, firewall IP blocks after failed attempts, 2FA problems and suspended accounts.

  BeginnercPanel and WHM2 min read

• Find and fix PHP errors using error_log on cPanel hosting

  Locate PHP errors in error_log files and cPanel Errors, read fatal errors and warnings correctly, enable safe debugging and fix the most common PHP messages.

  IntermediatecPanel hosting2 min read

• Troubleshoot Softaculous on WHM: licence, missing scripts and failed installs (root)

  Fix common server-side Softaculous problems as root: invalid licence, Softaculous missing in cPanel, outdated script lists, failed installs and stuck auto-upgrades.

  AdvancedWHM2 min read

• Start, stop, restart and power off a VPS in Virtualizor

  Understand the difference between Stop, Restart and Power Off in Virtualizor, when to use each, and what to do when a VPS will not start or is stuck.

  BeginnerVirtualizor VPS2 min read

• Fix 403 Forbidden errors on cPanel hosting

  Solve 403 Forbidden on a cPanel website: missing index file, wrong permissions, .htaccess deny rules, IP Blocker entries, hotlink protection or ModSecurity blocks.

  BeginnercPanel hosting2 min read

• WHMCS cron not running: how to find and fix the problem

  Diagnose why the WHMCS cron is not running or failing: check System Health, run cron.php manually, fix PHP binary, ionCube, paths, memory and locked tasks.

  AdvancedWHMCS2 min read

• Common email bounce errors explained (550, 552, 554, 421) on cPanel

  Understand the bounce messages you receive from cPanel mail servers: user unknown, mailbox full, SPF and DMARC failures, blocklists, rate limits and temporary deferrals.

  IntermediatecPanel hosting2 min read

• Fix the WordPress white screen of death

  Fix a blank white WordPress page step by step: find the error in the logs, disable plugins and the theme from File Manager, raise memory and restore if needed.

  IntermediatecPanel hosting3 min read

• Enable WordPress debug mode and read the debug log

  Turn on WP_DEBUG safely to find the plugin or theme behind an error: log to a private file, read debug.log, check PHP error logs in cPanel and switch it off.

  IntermediatecPanel hosting3 min read

• Fix "permission denied" on the Docker socket

  Fix the "permission denied while trying to connect to the Docker daemon socket" error. Add your user to the docker group, apply it without rebooting, and understand the security trade-off versus sudo.

  BeginnerLinux server4 min read

• Fix Docker daemon not starting

  Docker service failed to start? Read the real error with journalctl, then fix an invalid daemon.json, conflicting options, storage driver and overlay errors, a full disk or iptables problems.

  IntermediateLinux server5 min read

• Fix a Docker container that exits immediately

  Find out why a Docker container stops right after it starts. Read logs and exit codes, then fix missing environment variables, a wrong command, background processes and restart loops.

  BeginnerLinux server5 min read

• Fix the wrong keyboard layout in Remote Desktop

  Stop Remote Desktop switching to a US or wrong keyboard layout. Add your layout on the server, remove extras, set a default input method and tame Alt+Shift.

  BeginnerWindows server5 min read

• Get instant answers with MdmHost AI

  Use MdmHost AI at /ai for setup and troubleshooting questions at any time, learn how to ask questions that get useful answers, and know when to open a support ticket instead.

  Beginner4 min read

• Fix "cPanel license invalid" or licence not found errors

  Fix cPanel licence invalid or licence not found errors on a VPS. Check the IP on verify.cpanel.net, open outbound connections, fix DNS and time, and refresh with cpkeyclt.

  IntermediateLinux server4 min read

• Is your ISP or router blocking port 3389? How to tell

  Work out whether your internet provider, home router, parental controls or a proxy is blocking RDP port 3389, and collect the details support needs to help.

  IntermediateWindows server5 min read

Browse by topic

• Getting startedYour first hour with a new server: access, logins and basics.83 guides
• cPanelFiles, databases, email, domains and every cPanel tool, step by step.67 guides
• WHM & resellingWHM, packages, reseller accounts, WHMReseller and running a hosting brand.53 guides
• WordPressInstall, secure, speed up, migrate and fix WordPress sites.49 guides
• Email & webmailMailboxes, webmail, forwarders, spam filters and email delivery.67 guides
• DomainsRegistering, transferring and managing domains and nameservers.27 guides
• SSL certificatesFree AutoSSL, Let's Encrypt, paid certificates and HTTPS.41 guides
• CloudLinuxCloudLinux setup and use: LVE limits, CloudLinux Manager, CageFS and PHP/Node.js selectors.31 guides
• LiteSpeedLiteSpeed Web Server, LSCache and the LiteSpeed Cache plugin: install, settings and tuning.35 guides
• Imunify360Malware scanning, firewall and proactive defence with Imunify360.24 guides
• SoftaculousInstall, update, clone and back up apps with Softaculous.24 guides
• WP SquaredcPanel's WordPress platform: sites, plugins, staging and backups.9 guides
• SitePadBuild and publish websites with the SitePad builder.9 guides
• SitejetDesign, edit and publish sites with the Sitejet builder.9 guides
• WHMResellerAlpha and master resellers with WHMReseller: install, setup and use.12 guides
• VirtFusionInstall, set up and manage VirtFusion: hypervisors, packages, servers and WHMCS integration.28 guides
• VirtualizorManage your VPS with Virtualizor: power, OS reinstall, VNC, IPs and backups.44 guides
• PleskWebsites, email, databases and settings in the Plesk panel.53 guides
• DirectAdminUsers, domains, email and reseller tools in DirectAdmin.41 guides
• WHMCSBilling, automation, products and client management with WHMCS.52 guides
• Control panelscPanel & WHM, Plesk, DirectAdmin and other panels on your VPS.107 guides
• SecurityKeys, passwords, firewalls and keeping a server patched.138 guides
• Networking & DNSIP addresses, reverse DNS, ports and traffic.72 guides
• Websites & appsWeb servers, WordPress, PHP, Node.js, SSL and app hosting.83 guides
• DatabasesMySQL, MariaDB, PostgreSQL, Redis and MongoDB on a VPS.80 guides
• Billing & accountInvoices, renewals, the client area and your account.9 guides
• TroubleshootingWhen something is not working: checks and fixes.127 guides
• Linux VPSSSH, packages, services and everyday Linux administration.265 guides
• Windows VPS & RDPRemote Desktop, Windows Server settings and Admin RDP tips.73 guides
• Docker & DevOpsContainers, Git deploys, automation, monitoring and backups.82 guides