ArgumentNullException in UI Toolkit

When I use UI-Toolkit, this error occurs.

ArgumentNullException: Value cannot be null.
Parameter name: key
System.Collections.Generic.Dictionary`2[TKey,TValue].FindEntry (TKey key) (at <83161767e3f34f4a9c1453ea3e22d1f1>:0)
System.Collections.Generic.Dictionary`2[TKey,TValue].TryGetValue (TKey key, TValue& value) (at <83161767e3f34f4a9c1453ea3e22d1f1>:0)
UnityEngine.UIElements.TextureRegistry.Acquire (UnityEngine.Texture tex) (at <3a7f4a01e498464da8bf2ee951800f30>:0)
UnityEngine.UIElements.UIR.Implementation.UIRStylePainter.DrawTextInfo (UnityEngine.TextCore.Text.TextInfo textInfo, UnityEngine.Vector2 offset, System.Boolean useHints) (at <3a7f4a01e498464da8bf2ee951800f30>:0)
UnityEngine.UIElements.UIR.Implementation.UIRStylePainter.DrawText (UnityEngine.UIElements.TextElement te) (at <3a7f4a01e498464da8bf2ee951800f30>:0)
UnityEngine.UIElements.MeshGenerationContextUtils.Text (UnityEngine.UIElements.MeshGenerationContext mgc, UnityEngine.UIElements.TextElement te) (at <3a7f4a01e498464da8bf2ee951800f30>:0)
UnityEngine.UIElements.TextElement.OnGenerateVisualContent (UnityEngine.UIElements.MeshGenerationContext mgc) (at <3a7f4a01e498464da8bf2ee951800f30>:0)
UnityEngine.UIElements.VisualElement.InvokeGenerateVisualContent (UnityEngine.UIElements.MeshGenerationContext mgc) (at <3a7f4a01e498464da8bf2ee951800f30>:0)
UnityEngine.GUIUtility:ProcessEvent(Int32, IntPtr, Boolean&)

I have no idea why this happens. Can anybody help me?

I’m working with Unity-2022-2

Recreating my Font Assets fixed this error for me.