If you’ve ever launched SAMSON only to find that one of your favorite Extensions didn’t load, you’re not alone. As a molecular modeler, you often rely on a toolkit of Extensions to streamline simulations, visualize molecules, or access specific modeling workflows. When an expected Extension silently disappears, this can disrupt your work, leading to confusion and, sometimes, wasted time hunting for fixes.
This behavior is not a bug—it’s the result of how SAMSON ensures compatibility between its core version and Extensions built with different versions of its Software Development Kit (SDK). Understanding this system can help prevent workflow interruptions and give you better control over your computational toolset.
Version mismatches: what’s happening under the hood?
Every SAMSON Extension is built using a particular version of the SDK. When SAMSON starts, it checks whether the SDK version used to build each Extension is compatible with its own internal version.
Compatibility is determined based on two numbers: the major and minor versions. Generally:
- Major versions must match.
- SDK’s minor version must be less than or equal to SAMSON’s minor version.
For example, let’s say you’re running SAMSON version 1.7.8. Extensions built with SDK versions such as 1.3.5 or 1.7.7 are compatible. However, an Extension built with SDK 1.8.5 won’t load, because there may be functions in that SDK that SAMSON 1.7.8 doesn’t support yet.
Why this matters for molecular modelers
Extensions are the engine behind many structural analysis tools, visualization outputs, and simulation steps. Having one silently fail to load—especially one part of a workflow—can lead to confusion, especially when you’re preparing an important structure or collaborating with research partners.
By understanding the compatibility rules, you can avoid these interruptions. If you’re installing a new Extension and it doesn’t appear in your interface, check if it was built with a newer SDK version than your installed SAMSON. If so, you’ll need to update SAMSON to a compatible version.
Automatic updates and how they help
Fortunately, SAMSON can automatically update Extensions—but only when the new Extension version is compatible. For example:
- Your SAMSON version is
1.7.8 - You have installed an Extension built with SDK
1.5.2. - If a version built with SDK
1.6.4is published, SAMSON can update it at startup.
If a newer version of the Extension is built with SDK 2.0.0 and you haven’t updated SAMSON yet, it will not be updated. The existing compatible version will continue to work.
Simple tips to keep everything working
- Keep SAMSON up to date to expand compatibility with new Extension versions.
- Developers: be mindful of your SDK version and inform users if a new SAMSON version is required.
- If an Extension doesn’t load, check the SDK version used to build it against your SAMSON version.
For more details, visit the original documentation on SAMSON versioning and extension compatibility.
SAMSON and all SAMSON Extensions are free for non-commercial use. You can download SAMSON at https://www.samson-connect.net.