Standalone Profiler throws a NullReferenceException when saving Profiling data via top-menu after enabling or disabling UI Toolkit Live Reload option

Steps to reproduce:

1. Open the attached project
2. Open the Standalone Profiler window (Analysis -> Profiler (Standalone Process))
3. Enter Play mode and record a few frames
4. Pause the Recording
5. Right-click on the Standalone Profiler window's handle
6. Enable or disable the UI Toolkit Live reload option
7. In the Top Menu, select the option to save the recording (File -> Save to profile data file)
8. Observe the Console window

Actual results: NullReferenceException is thrown after saving the captured data

Expected results: No errors or warnings are thrown when saving the captured profiling data via the top menu

Reproducible with versions: 6000.3.0a5, 6000.3.23f1, 6000.5.10f1, 6000.6.0b10, 6000.7.0a5

Not reproducible with versions: 6000.0.82f1, 6000.3.0a4

Tested on (OS): macOS 26.6.2, Ubuntu 24

Notes:

• Saving the profiler data via the UI button inside the Profiler window does not reproduce the error