Was guts2-old.fsapi.com officially decommissioned in May 2026

jasmine

Hello,

We recently noticed that access to guts2-old.fsapi.com suddenly started returning HTTP 404 errors around May 2026.

We understand that this is a legacy update server and that end-of-support / migration notices were announced around 2024. However, the hostname had remained accessible until recently, so we would like to understand why it suddenly became unavailable at this timing.

Could anyone confirm whether:

• this was an officially scheduled shutdown,
• a DNS / CDN migration,
• or another intentional service retirement event?

We are investigating this behavior for compatibility and operational impact analysis, so any official information or timeline would be appreciated.

Thank you.

LiselotteP

Hi,

Thank you for the detailed question. There are actually two separate things happening with the GUTS2 infrastructure that are worth distinguishing.

1. The legacy guts2-old.fsapi.com shutdown — end of the extended support window

Support for all Business Suite products older than version 16 ended at the end of 2024. Part of this end-of-life process was the removal of old backend services for delivering updates. The internal communications at the time confirmed that guts2-old.fsapi.com was the one exception — kept running specifically to give legacy customers a final migration window until March 31, 2025. After that date, there was no published commitment to keep it operational. The 404 errors you are seeing are consistent with the hostname having been decommissioned following the close of that window. This was an intentional service retirement.

You can find the public record of this here: https://community.withsecure.com/en/kb/articles/31604-withsecure-business-suite-no-support-for-old-versions-15-x-and-older

2. A separate GUTS2 infrastructure change happening today

There is also an unrelated but coincidentally timed change happening specifically on May 19, 2026: WithSecure is transitioning the TLS certificates used by the GUTS2 server from DigiCert to Let's Encrypt certificates. The change is expected to be transparent for most environments, but may require action in environments with restricted certificate updates, custom trust stores, or where the ISRG Root X1 root certificate is missing or not trusted.

If your 404 errors started around today specifically, this TLS change may be a contributing factor depending on your environment's certificate trust configuration. The announcement is here: https://community.withsecure.com/announcements-en/kb/articles/32926-tls-certificate-provider-update-for-guts2-backend-may-19-2026

In summary: The guts2-old.fsapi.com hostname going dark is the expected conclusion of a decommission process announced in 2024/2025, and any systems still relying on it have not been receiving updates since at least March 31, 2025 regardless. If you are investigating operational impact, I'd recommend opening a support case so the team can review your specific environment.