Steps to reproduce:
1. Create new Unity project
2. Open Grid and Snap Settings in the Scene view window
3. In Grid Transform > Rotation X value type “Infinity”
4. Observe the Console window

Actual results: Entering “Infinity” in Rotation X/Y/Z values throws error in the Console window: “Assertion failed on expression: 'CompareApproximately(SqrMagnitude(result), 1.0F)'
UnityEditor.GUIView:ProcessEvent (UnityEngine.EntityId,intptr,bool&)”
Expected results: Rotation value fields reject non-finite values or event to previous valid value like “0”

Reproducible with versions: 6000.4.0b9, 6000.5.0a7
Can’t test with versions: 6000.3.9f1 and lower (Grid and Snap Settings not available)

Tested on (OS): Ubuntu 24.04, macOS Silicon Tahoe 26.2 (M1)

Notes:

•  when entering “Infinity” in Inspector > Transform Position, the value is set to 0, no errors are thrown in the Console window
• on 6000.5.0a7 spams extra unclearable errors and messages:

{code:java}
Quaternion To Matrix conversion failed because input Quaternion is invalid {-nan, -nan, -nan, -nan} l=-nan
UnityEngine.GUIUtility:ProcessEvent (UnityEngine.EntityId,intptr,bool&)
{code}

{code:java}
Look rotation viewing vector is zero
UnityEngine.Quaternion:Internal_LookRotation (UnityEngine.Vector3&,UnityEngine.Vector3&)
UnityEditorInternal.Slider2D:CalcDeltaAlongDirections (int,UnityEngine.Vector3,UnityEngine.Vector3,UnityEngine.Vector3,UnityEngine.Vector3,UnityEngine.Vector3,single,UnityEditor.Handles/CapFunction,UnityEngine.Vector2,bool) (at /home/bokken/build/output/unity/unity/Editor/Mono/Handles/Slider2D.cs:92)
UnityEditorInternal.Slider2D:Do (int,UnityEngine.Vector3,UnityEngine.Vector3,UnityEngine.Vector3,UnityEngine.Vector3,UnityEngine.Vector3,single,UnityEditor.Handles/CapFunction,UnityEngine.Vector2,bool) (at /home/bokken/build/output/unity/unity/Editor/Mono/Handles/Slider2D.cs:60)
UnityEngine.GUIUtility:ProcessEvent (UnityEngine.EntityId,intptr,bool&)
{code}