Windows protected your PC

And other antivirus troubles

On this page, you'll find typical problems with antiviruses and ways to solve them.

The add-in cannot load one of its dlls

After installation, on Excel startup, you may receive the following disturbing message:
The add-in cannot load one of its dlls

First of all, check if you are using the freshest version of Ultimate Suite for Excel, which you can find on our Downloads page. Here is the guide on how to find the version number installed on your machine. If you've got an older version, install the latest one.

If after this the dll error persists, see below the reasons it may happen and several ways to solve it.

Turn off the Mandatory ASLR option

The cause of the problem may be in the enabled Mandatory ASLR option, as Ultimate Suite binaries are not compatible with Mandatory ASLR.

Click the Start button and type in Windows Security:
Open Windows Security.

Click App & browser control:
Click App & browser control.

Find Exploit protection and click Exploit protection settings:
Exploit protection settings.

In System settings, find the Force randomization for images (Mandatory ASLR):
Force randomization for images (Mandatory ASLR).

Open the drop-down list and select Off by default:
Select Off by default.

Protection Error 253 with Trend Micro Antivirus

If you use the Trend Micro Antivirus, you may get the following error:
Protection Error 253.

If you see this, add the Ultimate Suite installation folder to the antivirus exceptions:
Trend Micro Antivirus exceptions.

Check your antivirus Quarantine

Despite the fact that our certificates are trusted, sometimes due to some reasons some antiviruses may block Ablebits. In such cases, you may get this message. Please go to Quarantine in your antivirus and restore all the Ablebits files you find there.

Disable the Preview pane in File Explorer

Besides, the cause of the problem may be the enabled Preview pane, so please disable it and try to install the add-in again.

Check your permissions

Also, you may not have the necessary permissions to run executable files from the installation folder. Consult your system administrator. If this doesn't help, please contact us at We will do our best to help you solve the problem.

Check the AppLocker settings (if you use it)

If you use Windows 10 Enterprise or Education, the problem may occur because of AppLocker blocking the Ablebits installer. You can find it out if you go to Computer Management -> Event Viewer -> Applications and Services Logs -> Microsoft -> Windows -> AppLocker. If in the Number of Events column, you can see any number other then 0, this means that AppLocker is set to block some types of files (.exe, .msi, .dll, etc.). In this case, please consult your system administrator.

Here is a short guide on How to configure AppLocker to let the add-in work correctly.

Windows protected your PC

This is the message you may get after you have downloaded our product and are trying to install it:
Windows protected your PC
Please don't be scared, everything is Okay. Simply click the More Info link, and you will see this:
Windows protected your PC-run anyway
And then, hit Run Anyway.

How to check that the certificate is valid

We publish our distributables in zip files. Please do not open a zip file directly in Windows Explorer. Instead, right-click it, and select Extract All... from the context menu. Then, switch to the Digital Signature tab of setup.exe Properties, select either signature, and click Details:
The Digital signature details
Now, click the View Certificate button:
Click View Certificate
And you will see the general information about the certificate:
General information about the certificate
On the Certification Path tab, select 4Bits Ltd. certificate:
4Bits Ltd. certificate
And make sure that the cert is valid.

The certificate and antiviruses

Also, some antivirus software may not allow running our setup.exe (or msi) because our certificate is not familiar to them. If your antivirus has blocked our product, please contact our support service at and we will promptly help you.

Unable to start the 'AblebitsMakeDiffs.exe' application

If while using Compare Two Sheets, you get the Unable to start the 'AblebitsMakeDiffs.exe' application error message, please follow this guide: Configure Microsoft Defender or Windows Defender to use Compare Two Sheets

Post a comment

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If you have any questions or issues with this add-in, please feel free to post your concerns in the comments area. As soon as we answer, a notification message will be sent to your e-mail. If you do not want to share your thoughts in public, please contact us at