Reproduction steps:
1. Open the user's attached project
2. Open the "SampleScene" Scene
3. Open the "Test Editor Window" from the menu bar
4. Attempt to drag a prefab by dragging the "Drag Me" button onto the Scene view and observe the Console

Expected result: no errors or warnings are shown
Actual result: 1 error and 2 warnings are shown

Reproducible with: 2021.2.0a17, 2021.2.0b13, 2022.1.0a10
Not reproducible with: 2021.2.0a16, 2020.3.19f1, 2021.1.22f1, 2021.2.0a16
Could not test with: 2019.4.30f1 and below (NullReferenceException error)

Error and warnings:
1. TLS Allocator ALLOC_TEMP_TLS, underlying allocator ALLOC_TEMP_MAIN has unfreed allocations, size 27
2. Internal: Stack allocator ALLOC_TEMP_MAIN has unfreed allocations, size 27
3. To Debug, enable the define: DEBUG_STACK_LEAK in StackAllocator.h. This will output the callstacks of the leaked allocations