When "Update Sprite Asset" is selected after creating "Sprite Asset" in the Inspector, it causes the editor to throw ArgumentOutOfRangeException, refer attached video.

Steps to reproduce:
1. Create a new project with 3D Template
2. Import any Texture in the project
3. Texture > Create > TextMeshPro > Sprite Asset
4. Select Sprite Asset > Inspector > Update Sprite Asset

Actual Result:
ArgumentOutOfRangeException is thrown on updating Sprite Asset

Expected Result:
Sprite Asset is updated without throwing any error in the console

Note: Update Sprite Asset is introduced in TMP package version: 3.0.0-preview.1

Occurring on:
2020.2.0a10, 2020.1.0b7, 2019.3.12f1 with package version 3.0.0-preview.11, 3.0.0-preview.5, 3.0.0-preview.1

Environment:
Windows10 and macOS 10.14

Stack trace:
ArgumentOutOfRangeException: Index was out of range. Must be non-negative and less than the size of the collection.
Parameter name: index
System.ThrowHelper.ThrowArgumentOutOfRangeException (System.ExceptionArgument argument, System.ExceptionResource resource) (at <fb001e01371b4adca20013e0ac763896>:0)
System.ThrowHelper.ThrowArgumentOutOfRangeException () (at <fb001e01371b4adca20013e0ac763896>:0)
TMPro.EditorUtilities.TMP_SpriteAssetMenu.UpdateSpriteAsset (TMPro.TMP_SpriteAsset spriteAsset) (at library/packagecache/com.unity.textmeshpro@3.0.0-preview.11/scripts/editor/tmp_spriteassetmenu.cs:144)
TMPro.EditorUtilities.TMP_SpriteAssetEditor.OnInspectorGUI () (at library/packagecache/com.unity.textmeshpro@3.0.0-preview.11/scripts/editor/tmp_spriteasseteditor.cs:121)
UnityEditor.UIElements.InspectorElement+<>c__DisplayClass58_0.<CreateIMGUIInspectorFromEditor>b__0 () (at <599a88f0dc984e9a84071cb802b80734>:0)
UnityEngine.GUIUtility:ProcessEvent(Int32, IntPtr, Boolean&)