Failed installation of FortiClient (VPN only)

Forum|Forum|7 months ago
January 6, 2026
5 replies
1890 views

I am trying to install a FortiClient (VPN only) FortiClient

I have downloaded the instalation file after filling the form https://www.fortinet.com/support/product-downloads#download-vpn-only

I have selected the Windows version.

When I launch the instalation file, it downloads image, unpack it, but then nothing happens.

FortiClient

Best answer by Jean-Philippe_P

Hello again DK0,

I found this solution. Can you tell us if it helps, please?

To address the issue where the FortiClient VPN Only installation does not proceed after unpacking, follow these steps:

Verify the Download: Ensure that the downloaded file is complete and not corrupted. You can do this by checking the file size and comparing it with the expected size on the download page.
Run as Administrator: Right-click on the installation file and select "Run as administrator" to ensure it has the necessary permissions to install.
Check for Temporary Files: During the initial execution, a temporary .msi file is created. Check the path C:\ProgramData\Applications\Cache\<Global Unique ID>\<FortiClient version and build number>\ for the .msi file. If found, try running the .msi file directly.
Disable Antivirus/Firewall: Temporarily disable any antivirus or firewall software that might be blocking the installation process.
Check for Known Issues: Refer to the known issues for your version. For example, in version 7.4.2, there are known issues with services not starting automatically after an upgrade. Ensure your system meets all requirements and workarounds are applied if necessary.
Re-download and Reinstall: If the above steps do not resolve the issue, try re-downloading the installation file and attempt the installation again.

If the problem persists, consider reaching out to Fortinet Support for further assistance.

Jean-Philippe_P

Staff & Editor

Hello DK0,

Thank you for using the Community Forum. I will seek to get you an answer or help. We will reply to this thread with an update as soon as possible.

Jean-Philippe - Fortinet Community Team

Jean-Philippe_P

Staff & Editor

Hello,

We are still looking for an answer to your question.

We will come back to you ASAP.

Jean-Philippe - Fortinet Community Team

Jean-Philippe_PAnswer

Staff & Editor

Hello again DK0,

I found this solution. Can you tell us if it helps, please?

To address the issue where the FortiClient VPN Only installation does not proceed after unpacking, follow these steps:

Verify the Download: Ensure that the downloaded file is complete and not corrupted. You can do this by checking the file size and comparing it with the expected size on the download page.
Run as Administrator: Right-click on the installation file and select "Run as administrator" to ensure it has the necessary permissions to install.
Check for Temporary Files: During the initial execution, a temporary .msi file is created. Check the path C:\ProgramData\Applications\Cache\<Global Unique ID>\<FortiClient version and build number>\ for the .msi file. If found, try running the .msi file directly.
Disable Antivirus/Firewall: Temporarily disable any antivirus or firewall software that might be blocking the installation process.
Check for Known Issues: Refer to the known issues for your version. For example, in version 7.4.2, there are known issues with services not starting automatically after an upgrade. Ensure your system meets all requirements and workarounds are applied if necessary.
Re-download and Reinstall: If the above steps do not resolve the issue, try re-downloading the installation file and attempt the installation again.

If the problem persists, consider reaching out to Fortinet Support for further assistance.

Jean-Philippe - Fortinet Community Team

DK0Author

New Member

Hi.

1. I did not found any number against which I should crosscheck the filesize. There is non in the download page

2. Done

3. That helped - I found the cache and launched the file, it ended up with error 2755. I have done a bit of search in this forum, tried to manually create the c:/windows/installer folder (which was not successfull - probably company policy) and trying to reinstall.

4. Not possible due to company policy (or I need to contact someone)

5. Where should I check? I have tried to search in this forum, but did not found neat page with know-issues