Server Security 15.30 - Server slow after Ultralight Core update

After the automated install of F-Secure Ultralight Core (64-bit) 2023-08-22_01 on 28.8.2023 one of our (web) servers is getting dead slow when under heavier load. Uninstalling Server Security restores the server performance but is of course not something that we want to do and this has never happened prior to the update mentioned above.
Reinstalling Server Security reintroduces the same problem when the update gets autoinstalled.

Is this something that someone else also has noted?

Accepted Answer

  • Sethu Laks
    Sethu Laks Posts: 125 Moderator
    edited September 1 Answer ✓

    Hi @Kjell

    We would like to notify you that a new version of Ultralight Core, specifically Ultralight Core 2023-08-31_01, has been released to the channel.

    The purpose of this update is to rollback the changes made in the previous problematic update, Ultralight Core 2023-08-22_01. By implementing this rollback, our aim is to address any customer issues that may have arisen after the problematic update was applied.

    Please ensure that the new version of Ultralight core has been installed on your machine.

    For further updates, we encourage you to monitor our status page here to stay informed about any developments.

    If you have any additional inquiries or require further assistance, please do not hesitate to reach out to us.

    Best regards,
    Community Moderator | Technical Support Engineer


  • BigWill
    BigWill Posts: 3 Observer

    We're having this on our 2016 Terminal Server. Server is grinding to a halt. Planning on uninstalling tonight after hours.

    Ultralight core 2023-08_22_01 was installed 7pm Monday night. Server slow as Tuesday morning.

  • Supersensible
    Supersensible Posts: 1 Observer

    We are having the exact same issue as mentioned here. WinServer 2016 after the F-Secure Ultralight Core (64-bit) 2023-08-22_01 on 28.8.2023 update. Will also have to uninstall if no fix in sight.

    Any incoming fixes?

  • JamesC
    JamesC Posts: 458 Moderator
    edited August 30

    Hi @Supersensible @BigWill @Kjell ,

    Thank you for reaching out to WithSecure community.

    We apologize for the inconvenience that this issue caused to you. Our partnership is very important for us.

    Our developers are aware of the issue and prioritising a fix.

    Can you please submit a case via with WSDiag log and share the case number to me via private message ?

  • Kjell
    Kjell Posts: 4 Explorer


    Server Security is currently uninstalled from the server in question and I would rather not install it again and cause performance issues for our users. The C:\ProgramData\F-Secure\Log directory still exists on the server so if there is something that I can pick from there and add to the case then please let me know. Should I add a case even if I don't have wsdiag.log?

  • BigWill
    BigWill Posts: 3 Observer

    Hi All,

    Spoke with Hans yesterday. Advised us we could roll back the ultralight core to the previous version.

    We have done that. Our speed has returned. We have blocked the auto-update server's address in our routers until the next version is released. Today will be a productive day in our office!

    Thanks Hans, You're a champ!

  • BigWill
    BigWill Posts: 3 Observer

    Hi @JamesC,

    I've sent accross the diag file with our existing case number.

    Hope this helps!

  • JamesC
    JamesC Posts: 458 Moderator

    Hi @BigWill , @Kjell , @Supersensible ,

    Appreciate your patience thus far. We apologize for the inconvenience that this issue caused to you. Our partnership is very important for us.

    R&D has reverted the ULCore update and the change is now in Production.

    If issue persists, you may try the following :

    1. Reinstall product and/or allow it to update to ULCore 2023-08-30_01, monitor the situation
    2. If it still reproduces, downgrade to ULCore 2023-07-06_01, see whether the issue still reproduces

  • Kjell
    Kjell Posts: 4 Explorer

    Hi @JamesC

    Thanks for your update.

    I installed Server Security again on the server and it updated ULCore to 2023-08-30_01. But I am sorry to say that the same performance issue was still there.

    I don't have the procedure for downgrading ULCore available so I uninstalled Server Security again and performance on the server was restored.

  • Kjell
    Kjell Posts: 4 Explorer

    Hi @Sethu Laks

    Just wanted to confirm that after updating our server with Ultralight Core 2023-08-31_01 the issue has been resolved. Thanks a lot for the swift fix and good communication in this thread.