When 3D models aren’t showing in addons, first ensure the addon is enabled and the model uses a supported format (e.g., .obj, .fbx).
Addons require explicit activation—double-check your software’s addon settings to confirm it’s on. Incompatible formats (like proprietary files) won’t load, so reference the addon’s docs for valid types.
If issues persist, move the model to the addon’s default directory (find the path in its documentation) or update both the addon and host software to resolve compatibility gaps.