Error message information on Malwarebytes for Windows

Tech Writer

Updated June 30, 2026 12:50

Compatible with:
Windows

The app provides error codes and messages for installation pre-requisites, installation, connection, activation, and authentication issues. This article describes the error messages including error code, description, and recommended resolution for the error encountered.

Installation pre-requisites error messages

Message/description	Resolution
The installer cannot be run from a network drive.	Install the app from the device's local hard drive.
Your system does not have enough free disk space to install the app.	Free up storage space on your device to install the app.
You do not have sufficient permissions (either disk or registry) to install Malwarebytes.	Install the app from a user profile with Admin permissions. Contact your system administrator, review Installation troubleshooting for Malwarebytes for Windows.
To complete the installation, your system may need to be restarted. Click Yes to continue anyway and you will be prompted when a restart is needed. Click No to cancel the installation.	Click Yes to continue the installation and restart after it completes. Click No to cancel the installation. Restart your device, then run the installer again.
Update Windows to stay protected. A missing Windows security update is required to update the app.	Check system requirements then try installing again.
Invalid path.	Submit a ticket with Support.
The installation failed to start. Please try running the installer again. For help troubleshooting please review the information at https://www.malwarebytes.com/help-installing	Follow installation troubleshooting information, then try installing again. Installation troubleshooting for Malwarebytes for Windows.
The installation failed. Please restart your system and try running the installer again. For help troubleshooting please review the information at https://www.malwarebytes.com/help-installing	Follow installation troubleshooting information, then try installing again. Installation troubleshooting for Malwarebytes for Windows.
Restart required. Malwarebytes must restart your computer to finish the installation. Some functionality may be limited until your computer restarts.	Restart your computer to complete the installation process.

Installation error messages

Message/description	Resolution
Malwarebytes for Windows does not support this system's CPU or hardware architecture.	Your ARM device is not supported. Install the app on another device.
This version of Windows is not supported.	The latest version of the app can't be installed on this device. Install the app on another device.
A corporate Malwarebytes product is already running on this computer.	A business version of Malwarebytes is already installed on your device. Uninstall the business version to install Malwarebytes for Windows.
An unsupported legacy version of the product has been detected. Please uninstall and then try again.	Uninstall the legacy version of the product before installing the latest version.
This version of Malwarebytes Anti-Ransomware is not compatible with a product that you currently have installed. The existing installation already includes Anti-Ransomware functionality and is incompatible with this version. Contact your System Administrator for assistance.	You are already running a Malwarebytes product that includes anti-ransomware protection. Contact your system administrator.
An error has occurred and Malwarebytes will not install on your computer.	Submit a ticket with Support.

Connection error messages including networking and general errors

Code	Message/description	Resolution
MB404104	Unable to contact license server. Check your network connection or contact your system administrator for help.	Check you have an active internet connection, and review Installation troubleshooting for Malwarebytes for Windows. If the issue persists, submit a ticket with Support.
	Unable to contact license server. Check your network settings or contact your system administrator for help.	Check you have an active internet connection, and review Installation troubleshooting for Malwarebytes for Windows. If the issue persists, submit a ticket with Support.
	Unable to contact update server. Check your proxy settings or contact your system administrator for help.	Check you have an active internet connection, and review Installation troubleshooting for Malwarebytes for Windows. If the issue persists, submit a ticket with Support.
	Unable to contact update server. Please check your internet connection.	Check you have an active internet connection, and review Installation troubleshooting for Malwarebytes for Windows. If the issue persists, submit a ticket with Support.

Activation error messages

Code	Message/description	Resolution
MB403100 MB403101	There's an issue with your license key. Please contact Support.	Submit a ticket with Support.
MB403101	Installation token not found.	Submit a ticket with Support.
MB403102	Your license key has expired.	Purchase a valid subscription. Visit our Pricing page.
MB403102	This license key does not match our records. Please make sure you entered it correctly.	Check your license details and try again. If the issue persists, submit a ticket with Support.
MB403102	Entitlement not found for this product.	Purchase a valid subscription. Visit our Pricing page.
MB403103	This license key does not match the product you are trying to activate.	Purchase a valid subscription. Visit our Pricing page.
MB403104	Device limit exceeded. You've reached the device limit for your subscription. Purchase another license or add another subscription.	Deactivate devices or purchase another subscription. See how to deactivate a device or visit our Pricing page.
MB403105	This license key has been refunded.	Purchase a valid subscription. Visit our Pricing page.
MB404102	The license key doesn't match our recording or has expired. Please purchase a new subscription and try again.	Purchase a valid subscription. Visit our Pricing page.
MB403101	You've hit your device limit. To activate Premium on this computer, log in to your account and deactivate another device or upgrade to a larger subscription.	Deactivate devices or purchase another subscription. See how to deactivate a device or visit our Pricing page.
MB404102	There isn't a subscription registered to your account. You can purchase a Malwarebytes subscription or register a license key to your account.	Purchase a valid subscription, visit our Pricing page, or add a license to your account.

Authentication error messages

Code	Message/description	Resolution
MB405100	You have reached the maximum amount of sign in attempts. To unlock your account, contact support.	Wait a minimum of 24 hours, then try to sign in again. If the issue persists, submit a ticket with Support.
MB405108	Verify your email and password are correct and try again.	Check your sign in credentials, then try to sign in again. If the issue persists, submit a ticket with Support.