If you’ve ever launched SAMSON and found that one of your favorite Extensions wasn’t loaded, even though it worked last week, you’re not alone. Molecular modelers relying on Extensions for simulations, visualizations, or custom tools may sometimes encounter this frustration. The culprit often lies in version compatibility between SAMSON and its Software Development Kit (SDK).
Understanding how SAMSON handles version compatibility can help you keep your Extensions functional—and your workflow uninterrupted.
Behind the Scenes: How Version Compatibility Works
Each SAMSON Extension is built using a specific version of the SAMSON SDK. SAMSON itself also uses the SDK internally. When you launch SAMSON, it checks whether its own SDK version is compatible with the SDK version used to build the Extension. If it’s not, the Extension simply won’t load.
The rule is simple:
- The major version number of SAMSON and the SDK used to build the Extension must be the same.
- The minor version number of the Extension’s SDK must be less than or equal to the minor version number used in SAMSON.
For example:
- ✅ Extension built with SDK 1.5.2 → Loads in SAMSON 1.7.8
- ✅ Extension built with SDK 1.7.7 → Loads in SAMSON 1.7.8
- ❌ Extension built with SDK 1.8.5 → Won’t load in SAMSON 1.7.8
Why? Because the newer SDK might use functions not available in your current SAMSON version, breaking compatibility.
How to Stay Compatible
To prevent loading issues:
- Update SAMSON regularly. This ensures you have the latest compatible environment for most Extensions.
- Let SAMSON auto-update Extensions. When compatible new versions of Extensions appear on SAMSON Connect, they’ll be loaded automatically at startup—if your SAMSON version is compatible.
- Watch major versions. When SAMSON moves from version 1.x.x to 2.x.x, some older Extensions built with version 1 might not load unless updated.
A Real Example
Let’s say you’re using SAMSON 1.7.8 and installed an Extension built with SDK 1.5.2. It works fine. But if a new version of the Extension is published on SAMSON Connect using SDK 2.0.0, what happens?
- If you don’t update SAMSON to 2.0.0, the new Extension won’t load.
- SAMSON will default back to the last compatible version (1.6.4, for instance).
This built-in strict compatibility check helps ensure stability and avoid crashes due to mismatched SDKs. But it also means users should stay vigilant, especially after new releases are announced.
How Extension Developers Can Help
Each Extension has its own version number too (major.minor.patch)—independent of the SDK version. Developers can use this to signal updates and improvements. But only the SDK version is checked for compatibility during SAMSON startup.
This means developers should clearly indicate what version of SAMSON is required, and ideally release compatible builds whenever SAMSON updates its SDK.
To learn more about how versioning works in SAMSON and what you can do to ensure compatibility, check out the full documentation:
https://documentation.samson-connect.net/users/latest/versioning/
SAMSON and all SAMSON Extensions are free for non-commercial use. You can get SAMSON at https://www.samson-connect.net.