Switching to a Previous Version of SAMSON: When Newer Isn’t Always Better

When it comes to molecular modeling and simulation, stability and compatibility are key. While keeping software up to date is generally good practice, there are situations where experienced modelers might need to revert to an earlier version of a tool — for example, to ensure compatibility with existing workflows or to use an Extension that’s no longer maintained for newer versions.

If you’re using SAMSON, the molecular design platform, and find yourself needing to install an earlier version, the good news is that the process is straightforward. In this post, we’ll walk you through how to install a previous version of SAMSON using the default installer, explain how versioning works in SAMSON, and help you ensure you’re always in control of your modeling environment.

Why use an older version?

Here are a few common scenarios:

• Your research depends on a specific version that passed internal validation.
• You’re collaborating with someone using a different version and need compatibility.
• A third-party Extension you rely on hasn’t yet been updated for the latest SAMSON release.

Installing an older version

You can use the SAMSON installer to install both the latest and earlier versions. Here’s how:

1. Download and launch the SAMSON Installer.
2. At the second step of the installation process, check the box that says Install an older version.
3. On the next screen, you’ll be able to select from a list of previous versions. Choose the one that best suits your needs.

Keep in mind the version names listed here use developer version numbers — for example, 2.0.2 corresponds to SAMSON 2021. You can check the full mapping of version numbers at the SAMSON User Guide versions page.

Launching multiple versions

If you have several versions of SAMSON installed, you can explicitly launch the one you need without altering your main setup. Here’s how to do it depending on your OS:

Windows

macOS

Linux

This gives you full flexibility to work with multiple projects tied to different versions, without disrupting your current default installation.

Final thoughts

Knowing how to install and manage different versions of SAMSON can save time and prevent compatibility headaches. Whether you’re collaborating across labs or relying on validated workflows, this feature ensures you won’t be stuck just because the software moved forward before you were ready.

For step-by-step details and other helpful tips, visit the official SAMSON FAQ page.

SAMSON and all SAMSON Extensions are free for non-commercial use. You can download the platform at www.samson-connect.net.