Reproduction steps:
1. Create a new project
2. Install Memory Profiler package (Window > Package Management > Package Manager > Unity Registry > Memory Profiler)
3. Window > Analysis > Memory Profiler
4. Click “Capture New Snapshot” button in Memory Profiler window
5. Click “Capture New Snapshot” button again
6. Select any of the captured Snapshots in the Snapshot list section
7. Continue selecting Snapshots repeatedly 5-10 times

Actual result: “TLS Allocator ALLOC_TEMP_TLS, underlying allocator ALLOC_TEMP_MAIN has unfreed allocations…” error and warnings are thrown
Expected result: No errors or warnings are thrown

Reproducible with: 1.1.11 (6000.3.0a2, 6000.3.11f1, 6000.4.0b11, 6000.5.0a8)
Not reproducible with: 1.1.8 (6000.3.0a1), 1.1.11 (6000.0.70f1, 6000.2.0a10)
Couldn’t reproduce with: 1.1.11 (6000.3.0a1) (Due to Memory Profiler package errors)

Reproduced on: Ubuntu 24.04
Not reproduced on: macOS Tahoe 26.3 (M4), Windows 11

IMPORTANT:

The error is a false positive and is the result of the TLS check being performed while (valid) allocations are still active.

Note:

• FAV is in Editor versions
• Full error:

{code:java}
TLS Allocator ALLOC_TEMP_TLS, underlying allocator ALLOC_TEMP_MAIN has unfreed allocations, size 55
UnityEditor.EditorUtility:DisplayProgressBar (string,string,single)
Unity.MemoryProfiler.Editor.UI.ProgressBarDisplay:UpdateProgress (single,string) (at ./Library/PackageCache/com.unity.memoryprofiler@3c0d9318643e/Editor/UI/ProgressBar/ProgressBar.cs:103)
Unity.MemoryProfiler.Editor.SnapshotDataService:LoadSnapshot (Unity.MemoryProfiler.Editor.Format.QueriedSnapshot.FileReader,bool) (at ./Library/PackageCache/com.unity.memoryprofiler@3c0d9318643e/Editor/UI/SnapshotDataService.cs:452)
Unity.MemoryProfiler.Editor.SnapshotDataService:Load (string) (at ./Library/PackageCache/com.unity.memoryprofiler@3c0d9318643e/Editor/UI/SnapshotDataService.cs:217)
Unity.MemoryProfiler.Editor.UI.SnapshotFileItemViewController:OpenCapture () (at ./Library/PackageCache/com.unity.memoryprofiler@3c0d9318643e/Editor/UI/Workbench/SnapshotFilesListItem/SnapshotFileTreeItemViewController.cs:291)
Unity.MemoryProfiler.Editor.UI.SnapshotFileItemViewController:<RefreshView>b__27_0 (UnityEngine.UIElements.MouseUpEvent) (at ./Library/PackageCache/com.unity.memoryprofiler@3c0d9318643e/Editor/UI/Workbench/SnapshotFilesListItem/SnapshotFileTreeItemViewController.cs:110)
UnityEngine.GUIUtility:ProcessEvent (int,intptr,bool&){code}

• Full warnings:

{code:java}
Internal: Stack allocator ALLOC_TEMP_MAIN has unfreed allocations, size 55{code}
{code:java}
To Debug, run app with -diag-temp-memory-leak-validation cmd line argument. This will output the callstacks of the leaked allocations.{code}