"ArgumentException: Can not deserialize" error is thrown on opening PBR Graph

Steps to reproduce:
1. Open an attached project or open ‘[Shader Graph] RQA’ project from Collab.
2. Project Window > ShaderGraphs > ConnectionTest.
3. Click on ‘Open Shader Editor’ in the inspector.

Note: Project link is given in comments.

Actual result:
“ArgumentException: Can not deserialize (UnityEditor.ShaderGraph.VoronoiNode), type is invalid” thrown in console.

Expected Result:
Shader Graph editor opens and no errors are thrown in console.

ShaderGraph package version: 5.7.2, 5.6.1

Reproducible in: 2019.1.0b8, 2019.1.0b7

Working fine in: 2019.2.0a8, 2019.1.0b6

Environment: Windows 10 and Mac 10.14

Stack trace:

1. ArgumentException: Can not deserialize (UnityEditor.ShaderGraph.VoronoiNode), type is invalid
UnityEditor.Graphing.SerializationHelper.Deserialize[T] (UnityEditor.Graphing.SerializationHelper+JSONSerializedElement item, System.Collections.Generic.Dictionary`2[TKey,TValue] remapper, System.Object[] constructorArgs) (at Library/PackageCache/com.unity.shadergraph@5.7.2/Editor/Data/Util/SerializationHelper.cs:103)
UnityEditor.Graphing.SerializationHelper.Deserialize[T] (System.Collections.Generic.IEnumerable`1[T] list, System.Collections.Generic.Dictionary`2[TKey,TValue] remapper, System.Object[] constructorArgs) (at Library/PackageCache/com.unity.shadergraph@5.7.2/Editor/Data/Util/SerializationHelper.cs:153)
UnityEngine.GUIUtility:ProcessEvent(Int32, IntPtr)

2. {
"m_GuidSerialized": "b1880318-f88a-4f5c-97fb-df1c0640fc07",
"m_Name": "Voronoi",
"m_DrawState": {
"m_Expanded": true,
"m_Position": {
"serializedVersion": "2",
"x": 146.03749084472657,
"y": 1618.4324951171875,
"width": 208.0,
"height": 326.0
}
},
"m_SerializableSlots": [
{
"typeInfo": {
"fullName": "UnityEditor.ShaderGraph.UVMaterialSlot"
},
"JSONnodeData": "{\n \"m_Id\": 0,\n \"m_DisplayName\": \"UV\",\n \"m_SlotType\": 0,\n \"m_Priority\": 2147483647,\n \"m_Hidden\": false,\n \"m_ShaderOutputName\": \"UV\",\n \"m_StageCapability\": 3,\n \"m_Value\": {\n \"x\": 0.0,\n \"y\": 0.0\n },\n \"m_DefaultValue\": {\n \"x\": 0.0,\n \"y\": 0.0\n },\n \"m_Labels\": [\n \"X\",\n \"Y\"\n ],\n \"m_Channel\": 0\n}"
},
{
"typeInfo": {
"fullName": "UnityEditor.ShaderGraph.Vector1MaterialSlot"
},
"JSONnodeData": "{\n \"m_Id\": 1,\n \"m_DisplayName\": \"Angle Offset\",\n \"m_SlotType\": 0,\n \"m_Priority\": 2147483647,\n \"m_Hidden\": false,\n \"m_ShaderOutputName\": \"AngleOffset\",\n \"m_StageCapability\": 3,\n \"m_Value\": 69.5999984741211,\n \"m_DefaultValue\": 2.0,\n \"m_Labels\": [\n \"X\"\n ]\n}"
},
{
"typeInfo": {
"fullName": "UnityEditor.ShaderGraph.Vector1MaterialSlot"
},
"JSONnodeData": "{\n \"m_Id\": 2,\n \"m_DisplayName\": \"Cell Density\",\n \"m_SlotType\": 0,\n \"m_Priority\": 2147483647,\n \"m_Hidden\": false,\n \"m_ShaderOutputName\": \"CellDensity\",\n \"m_StageCapability\": 3,\n \"m_Value\": 5.0,\n \"m_DefaultValue\": 5.0,\n \"m_Labels\": [\n \"X\"\n ]\n}"
},
{
"typeInfo": {
"fullName": "UnityEditor.ShaderGraph.Vector1MaterialSlot"
},
"JSONnodeData": "{\n \"m_Id\": 3,\n \"m_DisplayName\": \"Out\",\n \"m_SlotType\": 1,\n \"m_Priority\": 2147483647,\n \"m_Hidden\": false,\n \"m_ShaderOutputName\": \"Out\",\n \"m_StageCapability\": 3,\n \"m_Value\": 0.0,\n \"m_DefaultValue\": 0.0,\n \"m_Labels\": [\n \"X\"\n ]\n}"
},
{
"typeInfo": {
"fullName": "UnityEditor.ShaderGraph.Vector1MaterialSlot"
},
"JSONnodeData": "{\n \"m_Id\": 4,\n \"m_DisplayName\": \"Cells\",\n \"m_SlotType\": 1,\n \"m_Priority\": 2147483647,\n \"m_Hidden\": false,\n \"m_ShaderOutputName\": \"Cells\",\n \"m_StageCapability\": 3,\n \"m_Value\": 0.0,\n \"m_DefaultValue\": 0.0,\n \"m_Labels\": [\n \"X\"\n ]\n}"
}
],
"m_PreviewExpanded": true
}
UnityEngine.GUIUtility:ProcessEvent(Int32, IntPtr)