Game crashes with NullReferenceException in TextMeshPro after November 2025 update

Platform: PC (Windows 10/11, MTG Arena client)

Steps to Reproduce:

Launch MTG Arena after the November 2025 update.

Play a match normally.

At match end or when UI elements are destroyed/disabled, the client begins stuttering.

Within seconds, the game freezes and the entire computer becomes unresponsive.

Expected Result: Game should close connections and clean up UI/audio objects without crashing or freezing the system.

Actual Result:

Client stutters, then hard-freezes the PC.

Logs show repeated NullReferenceException errors in TMP_SubMeshUI.UpdateMaterial() and UnityEngine.Material.GetFloatImpl.

AudioManager fails to stop UI timer sounds on destroyed objects.

Network connections close normally, but the client terminates with Input System module state changed to: Shutdown.

Relevant Log Snippet:

Code
NullReferenceException
at UnityEngine.Material.GetFloat (System.String name)
at TMPro.TMPSubMeshUI.UpdateMaterial ()
at TMPro.TMPSubMeshUI.SetMaterialDirty ()
at UnityEngine.UI.MaskableGraphic.OnDisable ()
at TMPro.TMP_SubMeshUI.OnDisable ()
Additional Notes:

Issue began immediately after the November 2025 Avatar launch patch.

Repairing the client did not resolve the crash.

Suspect regression in Unity/TextMeshPro material handling during UI teardown.