[Bug] Antenna patterns disappear after saving KML or running simulation

[davidbits]

Affected Package / Scope

Desktop UI (fers-ui)

Bug Description

The antenna patterns stop rendering after exporting KML or running a simulation (likely happens elsewhere when the backend is called to export/import items). Going to the antenna property inspector shows "Backend is busy with another operation".

Steps to Reproduce

1. Launch fers-ui
2. Import example.fersxml (and frame scene)
3. Select IsotropicAntenna to show property inspector
4. Go to Simulation Run page
5. Generate KML
6. Return to Scenario Builder
7. Both (or maybe none, repeat if so) antenna patterns stop displaying and the property inspector shows "Backend is busy with another operation".
8. (note) using export scenario in scenario builder page fixes the issue

Expected vs. Actual Behavior (Optional)

No response

Environment (Optional)

• OS: Windows 11 x64
• MSVC v145