LoadFamily API method does not replicate manual family reload behavior

[kdbruin]

The API method LoadFamily(Document, IFamilyLoadOptions) (as of Revit 2026.4) does not seem to behave the same as the manual interface method for loading and upgrading families. When families are reloaded manually, parameter integrity is validated and parameter links remain intact. In addition, geometry changes in shared nested families are correctly updated when reloading the parent into the project.

The API method proves to be unreliable for reloading families in a project, as it only upgrades the parent family. We kindly request that the LoadFamily API method be updated to behave identically to the interface-based loading method.

[naveen.kumar.t]

Hi @kdbruin ,

It helps if it includes all the following:

• A short exact description of what you are trying to achieve.
• The behaviour you observe versus what you expect, and why this is a problem.
• A complete yet minimal Revit sample model to run a test in.
• A complete yet minimal Visual Studio solution with add-in manifest that can be compiled, loaded, run and debugged with a single click to analyse its behaviour live in the sample model.
• Detailed step-by-step instructions for reproducing the issue, e.g. which element to pick, what command to launch etc.

Thank you!