Invalid serialized file header. File: "VirtualArtifacts/Primary/*guid*".

[neon-age]

Got this after project Editor version update (from 2020.3 to 2021.1)

Invalid serialized file header. File: "VirtualArtifacts/Primary/46cdd7b95ede0f14390e6a26d6913911".
UnityEngine.StackTraceUtility:ExtractStackTrace ()
AV.UITK.FluentUITK:LoadAssetByGUID (System.Type,string) (at Library/PackageCache/com.av.smart-inspector@0.8.0/Runtime/Fluent UITK/FluentUITK.Utils.Assets.cs:89)
AV.UITK.FluentUITK:LoadAssetByGUID<UnityEngine.UIElements.StyleSheet> (string) (at Library/PackageCache/com.av.smart-inspector@0.8.0/Runtime/Fluent UITK/FluentUITK.Utils.Assets.cs:80)
AV.UITK.FluentUITK:FindAsset<UnityEngine.UIElements.StyleSheet> (string,string) (at Library/PackageCache/com.av.smart-inspector@0.8.0/Runtime/Fluent UITK/FluentUITK.Utils.Assets.cs:64)
AV.UITK.FluentUITK:FindStyleSheet (string,string) (at Library/PackageCache/com.av.smart-inspector@0.8.0/Runtime/Fluent UITK/FluentUITK.Utils.Assets.cs:22)
AV.Inspector.Runtime.SmartInspector:FindStyleSheet (string,string) (at Library/PackageCache/com.av.smart-inspector@0.8.0/Runtime/SmartInspector.Utils.Assets.cs:16)
AV.Inspector.SmartInspector:get_scrollViewStyles () (at Library/PackageCache/com.av.smart-inspector@0.8.0/Base/SmartInspector.Resources.cs:9)
AV.Inspector.SmartInspector:DisplayOptionalParts () (at Library/PackageCache/com.av.smart-inspector@0.8.0/Base/SmartInspector.cs:301)
AV.Inspector.SmartInspector:OnRebuildContent (AV.Inspector.SmartInspector/RebuildStage) (at Library/PackageCache/com.av.smart-inspector@0.8.0/Base/SmartInspector.cs:229)
AV.Inspector.PropertyEditorPatch:_RebuildContentsContainers (UnityEditor.EditorWindow) (at Library/PackageCache/com.av.smart-inspector@0.8.0/Patches/PropertyEditorPatch.cs:60)
(wrapper dynamic-method) UnityEditor.PropertyEditor:UnityEditor.PropertyEditor.RebuildContentsContainers_Patch2 (UnityEditor.PropertyEditor)
UnityEditor.InspectorWindow:RedrawFromNative ()

[neon-age]

Package reimport fixes it??