Nothing seems to happen
AdFender is probably already running. It lives in the system tray, near the clock — if you do not see the icon, click the small arrow beside the clock to show hidden icons. Right-click the AdFender icon and choose Open dashboard.
If AdFender does not start with Windows, open Settings and turn on Launch at Windows startup.
“The AdFender window cannot be opened”
The full message says the Microsoft Edge WebView2 Runtime is missing or damaged. WebView2 is the Windows component that draws AdFender’s window. The message also says the important part: filtering is still running. This error affects only the window; filtering carries on unless something else has stopped it.
To get the window back, run AdFender’s installer again with the PC connected to the internet. Setup checks for WebView2 and installs it when it is missing. Installing the Microsoft Edge WebView2 Runtime yourself works too.
“Cannot start AdFender due to module version mismatch”
AdFender checks at startup that all its parts belong to the same version. This message means one of them is missing or from a different version. There are two usual reasons.
- An update is waiting for a restart. If you have just installed or updated AdFender, restart Windows and open AdFender again. That finishes the update, and is usually the end of it.
- Security software has moved one of AdFender’s files. AdFender attaches to your browsers to filter them, and some security software is wary of that and puts one of its files into quarantine. Look in your security software’s quarantine or history for a file from AdFender, restore it, and allow AdFender.
If neither applies, do what the message suggests: uninstall AdFender, restart Windows, and install the latest version. When the uninstaller asks whether to also remove your settings, answer No to keep them. Your license stays with the PC.
“AdFender was installed for another user account on this PC”
AdFender was installed with Install for me only from a different Windows account, so it works only there. To use it from more than one account, sign in with an administrator account, run AdFender’s installer again, and choose Install for all users of this computer.
That choice shares HTTPS filtering between the accounts on the PC. Installing and uninstalling explains what that means before you pick it.
“AdFender cannot start because another program on this PC has taken a system resource”
Another program is holding on to something AdFender needs in order to start. As the message says, it is not a second copy of AdFender. Restart Windows and open AdFender again; that usually clears it. If the message comes back after a restart, write to us and include the full message.
Configuration files, filter lists or the proxy
AdFender can stop at startup with one of these:
- One or more of your AdFender configuration files appear to be missing and/or corrupted.
- Error in loading filter lists.
- Error in loading TLD file.
- Unable to start proxy successfully.
Restart Windows and try again first. If the message comes back, download AdFender and run the installer over the copy you have, which repairs AdFender’s program files and keeps your settings and license. If the same message returns, write to us with its exact wording.
“AdFender requires Windows 10 or later”
AdFender 3.0 runs on Windows 10 and Windows 11 only. See common questions for older versions of Windows.
It starts, but says Protection is off
Then AdFender is running properly and the license is what stopped it, including the startup messages that end Please reactivate your license. License messages and what they mean covers each one.
Still stuck
Write to support@adfender.com with the exact wording of the message, your Windows version, and what you have tried. A screenshot of the message is just as good.