“Multiple instances of EditorPlayModeGuard detected. There should only be one instance.” error is thrown when deleting a default Play Mode Scenario and selecting another one as the default

Unity: Multiplayer Play Mode

Open

6.6.X

6.5.X

6.4.X

6000.4.0a2 onwards

In Progress

6.7.X

Reproduction steps:
1. Create a new project
2. Install Multiplayer Play Mode package (Window > Package Management > Package Manager)
3. Click on “Default Play Mode” button and select “Configure Play Mode Scenarios” option to open Play Mode Scenarios window
4. Create two new Play Mode Scenarios
5. Select one of the newly created Play Mode Scenarios as the default one
6. Open Play Mode Scenarios window again and delete the default Play Mode Scenario
7. Select another Play Mode Scenario as the default one
8. Observe the Console

Actual result: “Multiple instances of EditorPlayModeGuard detected. There should only be one instance.” error is thrown
Expected result: No errors or warnings are thrown

Reproducible with: 2.0.2 (6000.4.0a2, 6000.4.11f1, 6000.5.0b12), 3.0.0 (6000.6.0a7)
Not reproducible with: 1.6.3 (6000.0.76f1), 2.0.2 (6000.3.17f1, 6000.4.0a1)

Reproduced on: macOS Tahoe 26.5 (M4), Windows 11

Note:

FAV is in Editor versions
Full error:

Multiple instances of EditorPlayModeGuard detected. There should only be one instance.
UnityEngine.Debug:LogError (object)
Unity.Multiplayer.PlayMode.Editor.EditorPlayModeGuard:AssertSingleton () (at /Users/bokken/build/output/unity/unity/Modules/MultiplayerEditor/Managed/MultiplayerPlayMode/PlayModeConfig/EditorPlayModeGuard.cs:59)
Unity.Multiplayer.PlayMode.Editor.EditorPlayModeGuard:OnEnable () (at /Users/bokken/build/output/unity/unity/Modules/MultiplayerEditor/Managed/MultiplayerPlayMode/PlayModeConfig/EditorPlayModeGuard.cs:43)
UnityEngine.ScriptableObject:CreateInstance<Unity.Multiplayer.PlayMode.Editor.EditorPlayModeGuard> ()
Unity.Multiplayer.PlayMode.Editor.OrchestratedScenario:OnSelected () (at /Users/bokken/build/output/unity/unity/Modules/MultiplayerEditor/Managed/MultiplayerPlayMode/PlayModeConfig/OrchestratedScenario/OrchestratedScenario.cs:176)
Unity.PlayMode.Editor.ScenarioManagerProvider:AssignActiveConfig (Unity.PlayMode.Editor.PlayModeScenario) (at /Users/bokken/build/output/unity/unity/Modules/PlayModeEditor/Managed/Scenarios/ScenarioManagerProvider.cs:103)
Unity.PlayMode.Editor.ScenarioManagerProvider:set_ActivePlayModeConfig (Unity.PlayMode.Editor.PlayModeScenario) (at /Users/bokken/build/output/unity/unity/Modules/PlayModeEditor/Managed/Scenarios/ScenarioManagerProvider.cs:86)
Unity.PlayMode.Editor.PlayModeScenarioManager:set_ActiveScenario (Unity.PlayMode.Editor.PlayModeScenario) (at /Users/bokken/build/output/unity/unity/Modules/PlayModeEditor/Managed/Scenarios/PlayModeScenarioManager.cs:96)
Unity.PlayMode.Editor.PlaymodePopupContent:OnItemSelected (System.Collections.Generic.IEnumerable`1<object>) (at /Users/bokken/build/output/unity/unity/Modules/PlayModeEditor/Managed/Scenarios/UI/Toolbar/PlayModePopupContent.cs:90)
UnityEditor.GUIView:ProcessEvent (UnityEngine.EntityId,intptr,bool&) (at /Users/bokken/build/output/unity/unity/Editor/Mono/GUIView.cs:70)

“Multiple instances of EditorPlayModeGuard detected. There should only be one instance.” error is thrown when deleting a default Play Mode Scenario and selecting another one as the default

Unity: Multiplayer Play Mode

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In Progress

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“Multiple instances of EditorPlayModeGuard detected. There should only be one instance.” error is thrown when deleting a default Play Mode Scenario and selecting another one as the default

Unity: Multiplayer Play Mode

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Open

In Progress

Resolution Notes

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Have a workaround or additional info about this issue?