Bug Shader Graph unresponsive for all shaders in a project

I thought I'd post here before submitting a bug report since it's hard to narrow down a repro in other projects, and it will take a long time to attach my project. Just wondering if there's some easy fix that I missed in my searching.

While working on a Shader Graph in my project (Unity 2020.01b3.3385), I noticed that I could not let go of a node once I started dragging it. Most buttons in Shader Graph don't seem to work, I'm not able to drag links between nodes, not able to hit Save Asset, etc. This unfortunately applies to all Shader Graphs in the project.

Here's what I've tried in order to resolve:
- Closing Unity, then renaming "Library" folder in the project to "Library_backup". Did not fix after reopening Unity.
- Project Settings > Graphics > Reset. Did not fix.
- Created a new PBR Shader Graph. Did not fix.
- Created a new Unlit Shader Graph. Did not fix.
- Removing all existing shader graphs from my project, then create a new PBR Shader Graph. Did not fix.
- Creating a new URP project, then bringing in the Shader Graphs from my real project. The Shader Graphs from my real project work fine in the new project, which might point to the issue being related to Unity's project settings or some metadata in the project. Either way, it seems that it's not an issue with the Shader Graphs I was creating.

Attached below are two console statements. Let me know if there's anything else that would be helpful.

This shows up when I try to click away while dragging a node.

ArgumentNullException: Value cannot be null.

Parameter name: identifier

UnityEditor.Undo.RegisterCompleteObjectUndo (UnityEngine.Object objectToUndo, System.String name) (at <e2353c5c084f4b5a9d8ead9c6b8ffaa2>:0)

UnityEditor.Graphing.GraphObject.RegisterCompleteObjectUndo (System.String actionName) (at Library/PackageCache/com.unity.shadergraph@8.0.1/Editor/Data/Implementation/GraphObject.cs:51)

UnityEditor.ShaderGraph.Drawing.GraphEditorView.GraphViewChanged (UnityEditor.Experimental.GraphView.GraphViewChange graphViewChange) (at Library/PackageCache/com.unity.shadergraph@8.0.1/Editor/Drawing/Views/GraphEditorView.cs:380)

UnityEditor.Experimental.GraphView.SelectionDragger.OnMouseUp (UnityEngine.UIElements.MouseUpEvent evt) (at <e2353c5c084f4b5a9d8ead9c6b8ffaa2>:0)

UnityEngine.UIElements.EventCallbackFunctor`1[TEventType].Invoke (UnityEngine.UIElements.EventBase evt) (at <53e0fbd5e130421e81a0b5c1afcf22ee>:0)

UnityEngine.UIElements.EventCallbackRegistry.InvokeCallbacks (UnityEngine.UIElements.EventBase evt) (at <53e0fbd5e130421e81a0b5c1afcf22ee>:0)

UnityEngine.UIElements.CallbackEventHandler.HandleEvent (UnityEngine.UIElements.EventBase evt) (at <53e0fbd5e130421e81a0b5c1afcf22ee>:0)

UnityEngine.UIElements.CallbackEventHandler.HandleEventAtTargetPhase (UnityEngine.UIElements.EventBase evt) (at <53e0fbd5e130421e81a0b5c1afcf22ee>:0)

UnityEngine.UIElements.MouseCaptureDispatchingStrategy.DispatchEvent (UnityEngine.UIElements.EventBase evt, UnityEngine.UIElements.IPanel panel) (at <53e0fbd5e130421e81a0b5c1afcf22ee>:0)

UnityEngine.UIElements.EventDispatcher.ApplyDispatchingStrategies (UnityEngine.UIElements.EventBase evt, UnityEngine.UIElements.IPanel panel, System.Boolean imguiEventIsInitiallyUsed) (at <53e0fbd5e130421e81a0b5c1afcf22ee>:0)

UnityEngine.UIElements.EventDispatcher.ProcessEvent (UnityEngine.UIElements.EventBase evt, UnityEngine.UIElements.IPanel panel) (at <53e0fbd5e130421e81a0b5c1afcf22ee>:0)

UnityEngine.UIElements.EventDispatcher.ProcessEventQueue () (at <53e0fbd5e130421e81a0b5c1afcf22ee>:0)

UnityEngine.UIElements.EventDispatcher.OpenGate () (at <53e0fbd5e130421e81a0b5c1afcf22ee>:0)

UnityEngine.UIElements.EventDispatcherGate.Dispose () (at <53e0fbd5e130421e81a0b5c1afcf22ee>:0)

UnityEngine.UIElements.EventDispatcher.ProcessEvent (UnityEngine.UIElements.EventBase evt, UnityEngine.UIElements.IPanel panel) (at <53e0fbd5e130421e81a0b5c1afcf22ee>:0)

UnityEngine.UIElements.EventDispatcher.Dispatch (UnityEngine.UIElements.EventBase evt, UnityEngine.UIElements.IPanel panel, UnityEngine.UIElements.DispatchMode dispatchMode) (at <53e0fbd5e130421e81a0b5c1afcf22ee>:0)

UnityEngine.UIElements.BaseVisualElementPanel.SendEvent (UnityEngine.UIElements.EventBase e, UnityEngine.UIElements.DispatchMode dispatchMode) (at <53e0fbd5e130421e81a0b5c1afcf22ee>:0)

UnityEngine.UIElements.UIElementsUtility.DoDispatch (UnityEngine.UIElements.BaseVisualElementPanel panel) (at <53e0fbd5e130421e81a0b5c1afcf22ee>:0)

UnityEngine.UIElements.UIElementsUtility.UnityEngine.UIElements.IUIElementsUtility.ProcessEvent (System.Int32 instanceID, System.IntPtr nativeEventPtr, System.Boolean& eventHandled) (at <53e0fbd5e130421e81a0b5c1afcf22ee>:0)

UnityEngine.UIElements.UIEventRegistration.ProcessEvent (System.Int32 instanceID, System.IntPtr nativeEventPtr) (at <53e0fbd5e130421e81a0b5c1afcf22ee>:0)

UnityEngine.UIElements.UIEventRegistration+<>c.<.cctor>b__1_2 (System.Int32 i, System.IntPtr ptr) (at <53e0fbd5e130421e81a0b5c1afcf22ee>:0)

UnityEngine.GUIUtility.ProcessEvent (System.Int32 instanceID, System.IntPtr nativeEventPtr, System.Boolean& result) (at <e05e25897e384e2a862b8ea3613fb25c>:0)

And this is what shows up when I click Save Asset:

NullReferenceException: Object reference not set to an instance of an object

UnityEditor.ShaderGraph.Drawing.MaterialGraphEditWindow.IsDirty () (at Library/PackageCache/com.unity.shadergraph@8.0.1/Editor/Drawing/MaterialGraphEditWindow.cs:255)

UnityEditor.ShaderGraph.Drawing.MaterialGraphEditWindow.UpdateTitle () (at Library/PackageCache/com.unity.shadergraph@8.0.1/Editor/Drawing/MaterialGraphEditWindow.cs:275)

UnityEditor.ShaderGraph.Drawing.MaterialGraphEditWindow.UpdateAsset () (at Library/PackageCache/com.unity.shadergraph@8.0.1/Editor/Drawing/MaterialGraphEditWindow.cs:360)

UnityEditor.ShaderGraph.Drawing.GraphEditorView+<>c__DisplayClass48_1.<.ctor>b__0 () (at Library/PackageCache/com.unity.shadergraph@8.0.1/Editor/Drawing/Views/GraphEditorView.cs:151)

UnityEngine.UIElements.IMGUIContainer.DoOnGUI (UnityEngine.Event evt, UnityEngine.Matrix4x4 parentTransform, UnityEngine.Rect clippingRect, System.Boolean isComputingLayout, UnityEngine.Rect layoutSize, System.Action onGUIHandler, System.Boolean canAffectFocus) (at <53e0fbd5e130421e81a0b5c1afcf22ee>:0)

UnityEngine.UIElements.IMGUIContainer.HandleIMGUIEvent (UnityEngine.Event e, UnityEngine.Matrix4x4 worldTransform, UnityEngine.Rect clippingRect, System.Action onGUIHandler, System.Boolean canAffectFocus) (at <53e0fbd5e130421e81a0b5c1afcf22ee>:0)

UnityEngine.UIElements.IMGUIContainer.HandleIMGUIEvent (UnityEngine.Event e, System.Action onGUIHandler, System.Boolean canAffectFocus) (at <53e0fbd5e130421e81a0b5c1afcf22ee>:0)

UnityEngine.UIElements.IMGUIContainer.HandleIMGUIEvent (UnityEngine.Event e, System.Boolean canAffectFocus) (at <53e0fbd5e130421e81a0b5c1afcf22ee>:0)

UnityEngine.UIElements.IMGUIContainer.SendEventToIMGUIRaw (UnityEngine.UIElements.EventBase evt, System.Boolean canAffectFocus, System.Boolean verifyBounds) (at <53e0fbd5e130421e81a0b5c1afcf22ee>:0)

UnityEngine.UIElements.IMGUIContainer.SendEventToIMGUI (UnityEngine.UIElements.EventBase evt, System.Boolean canAffectFocus, System.Boolean verifyBounds) (at <53e0fbd5e130421e81a0b5c1afcf22ee>:0)

UnityEngine.UIElements.IMGUIContainer.HandleEvent (UnityEngine.UIElements.EventBase evt) (at <53e0fbd5e130421e81a0b5c1afcf22ee>:0)

UnityEngine.UIElements.CallbackEventHandler.HandleEventAtTargetPhase (UnityEngine.UIElements.EventBase evt) (at <53e0fbd5e130421e81a0b5c1afcf22ee>:0)

UnityEngine.UIElements.MouseCaptureDispatchingStrategy.DispatchEvent (UnityEngine.UIElements.EventBase evt, UnityEngine.UIElements.IPanel panel) (at <53e0fbd5e130421e81a0b5c1afcf22ee>:0)

UnityEngine.UIElements.EventDispatcher.ApplyDispatchingStrategies (UnityEngine.UIElements.EventBase evt, UnityEngine.UIElements.IPanel panel, System.Boolean imguiEventIsInitiallyUsed) (at <53e0fbd5e130421e81a0b5c1afcf22ee>:0)

UnityEngine.UIElements.EventDispatcher.ProcessEvent (UnityEngine.UIElements.EventBase evt, UnityEngine.UIElements.IPanel panel) (at <53e0fbd5e130421e81a0b5c1afcf22ee>:0)

UnityEngine.UIElements.EventDispatcher.ProcessEventQueue () (at <53e0fbd5e130421e81a0b5c1afcf22ee>:0)

UnityEngine.UIElements.EventDispatcher.OpenGate () (at <53e0fbd5e130421e81a0b5c1afcf22ee>:0)

UnityEngine.UIElements.EventDispatcherGate.Dispose () (at <53e0fbd5e130421e81a0b5c1afcf22ee>:0)

UnityEngine.UIElements.EventDispatcher.ProcessEvent (UnityEngine.UIElements.EventBase evt, UnityEngine.UIElements.IPanel panel) (at <53e0fbd5e130421e81a0b5c1afcf22ee>:0)

UnityEngine.UIElements.EventDispatcher.Dispatch (UnityEngine.UIElements.EventBase evt, UnityEngine.UIElements.IPanel panel, UnityEngine.UIElements.DispatchMode dispatchMode) (at <53e0fbd5e130421e81a0b5c1afcf22ee>:0)

UnityEngine.UIElements.BaseVisualElementPanel.SendEvent (UnityEngine.UIElements.EventBase e, UnityEngine.UIElements.DispatchMode dispatchMode) (at <53e0fbd5e130421e81a0b5c1afcf22ee>:0)

UnityEngine.UIElements.UIElementsUtility.DoDispatch (UnityEngine.UIElements.BaseVisualElementPanel panel) (at <53e0fbd5e130421e81a0b5c1afcf22ee>:0)

UnityEngine.UIElements.UIElementsUtility.UnityEngine.UIElements.IUIElementsUtility.ProcessEvent (System.Int32 instanceID, System.IntPtr nativeEventPtr, System.Boolean& eventHandled) (at <53e0fbd5e130421e81a0b5c1afcf22ee>:0)

UnityEngine.UIElements.UIEventRegistration.ProcessEvent (System.Int32 instanceID, System.IntPtr nativeEventPtr) (at <53e0fbd5e130421e81a0b5c1afcf22ee>:0)

UnityEngine.UIElements.UIEventRegistration+<>c.<.cctor>b__1_2 (System.Int32 i, System.IntPtr ptr) (at <53e0fbd5e130421e81a0b5c1afcf22ee>:0)

UnityEngine.GUIUtility.ProcessEvent (System.Int32 instanceID, System.IntPtr nativeEventPtr, System.Boolean& result) (at <e05e25897e384e2a862b8ea3613fb25c>:0)

 

I also have this issue in 2020.1.0b4

 

Same here:

ArgumentNullException: Value cannot be null.
Parameter name: identifier
UnityEditor.Undo.RegisterCompleteObjectUndo (UnityEngine.Object objectToUndo, System.String name) (at <f4f65bdffc5b446a881dc828be3f537e>:0)
UnityEditor.Graphing.GraphObject.RegisterCompleteObjectUndo (System.String actionName) (at Library/PackageCache/com.unity.shadergraph@8.0.1/Editor/Data/Implementation/GraphObject.cs:51)
UnityEditor.ShaderGraph.Drawing.MaterialGraphView.DeleteSelectionImplementation (System.String operationName, UnityEditor.Experimental.GraphView.GraphView+AskUser askUser) (at Library/PackageCache/com.unity.shadergraph@8.0.1/Editor/Drawing/Views/MaterialGraphView.cs:621)
UnityEditor.Experimental.GraphView.GraphView.DeleteSelectionOperation (System.String operationName, UnityEditor.Experimental.GraphView.GraphView+AskUser askUser) (at <f4f65bdffc5b446a881dc828be3f537e>:0)
UnityEditor.Experimental.GraphView.GraphView.DeleteSelectionCallback (UnityEditor.Experimental.GraphView.GraphView+AskUser askUser) (at <f4f65bdffc5b446a881dc828be3f537e>:0)
UnityEditor.Experimental.GraphView.GraphView.<BuildContextualMenu>b__156_6 (UnityEngine.UIElements.DropdownMenuAction a) (at <f4f65bdffc5b446a881dc828be3f537e>:0)
UnityEngine.UIElements.DropdownMenuAction.Execute () (at <06f736509a734c608f8b4e0dff8f746d>:0)
UnityEditor.UIElements.EditorMenuExtensions+<>c__DisplayClass0_0.<PrepareMenu>b__0 () (at <f4f65bdffc5b446a881dc828be3f537e>:0)
UnityEditor.GenericMenu.CatchMenu (System.Object userData, System.String[] options, System.Int32 selected) (at <f4f65bdffc5b446a881dc828be3f537e>:0)

 

Problem was fixed for me in Shader Graph 8.1.0