VRC Unity SDK Export error

ArgumentException: Path is empty
System.IO.FileStream..ctor (System.String path, System.IO.FileMode mode, System.IO.FileAccess access, System.IO.FileShare share, System.Int32 bufferSize, System.Boolean anonymous, System.IO.FileOptions options) (at <c3c5b887e5d443c09cc543e880304c86>:0)
System.IO.FileStream..ctor (System.String path, System.IO.FileMode mode, System.IO.FileAccess access, System.IO.FileShare share, System.Int32 bufferSize) (at <c3c5b887e5d443c09cc543e880304c86>:0)
(wrapper remoting-invoke-with-check) System.IO.FileStream..ctor(string,System.IO.FileMode,System.IO.FileAccess,System.IO.FileShare,int)
System.IO.File.ReadAllBytes (System.String path) (at <c3c5b887e5d443c09cc543e880304c86>:0)
VRC.SDKBase.Editor.Elements.Thumbnail.SetImage (System.String imagePath) (at ./Packages/com.vrchat.base/Editor/VRCSDK/Dependencies/VRChat/Elements/Thumbnail/Thumbnail.cs:162)
VRC.SDK3A.Editor.VRCSdkControlPanelAvatarBuilder.RevertThumbnail () (at ./Packages/com.vrchat.avatars/Editor/VRCSDK/SDK3A/VRCSdkControlPanelAvatarBuilder.cs:2337)
System.Runtime.CompilerServices.AsyncMethodBuilderCore+<>c.<ThrowAsync>b__7_0 (System.Object state) (at <c3c5b887e5d443c09cc543e880304c86>:0)
UnityEngine.UnitySynchronizationContext+WorkRequest.Invoke () (at /home/bokken/build/output/unity/unity/Runtime/Export/Scripting/UnitySynchronizationContext.cs:153)
UnityEngine.UnitySynchronizationContext.Exec () (at /home/bokken/build/output/unity/unity/Runtime/Export/Scripting/UnitySynchronizationContext.cs:83)
UnityEngine.UnitySynchronizationContext.ExecuteTasks () (at /home/bokken/build/output/unity/unity/Runtime/Export/Scripting/UnitySynchronizationContext.cs:107)