compatibility fixes for Unity 5.6.7f1 (and maybe earlier?)... still some errors from serialization ("Unknown API compatibility level: 6") from making everything in Unity 2019, but that's to be expected since everything breaks from Unity 2018.2 > Unity 2018.3... anyway, probably won't be fixing this, and no one else uses 5.6 anyway except me so whatever

Author: yangrobertw

Editor/Scripts/IvyCore.cs

@@ -719,7 +719,7 @@ public static bool IsPartOfPrefab(GameObject go) {
 					return false;
 				}
 			#else // uses old prefab workflow
-				return PrefabUtility.GetPrefabType(go) =! PrefabType.None;
+				return PrefabUtility.GetPrefabType(go) != PrefabType.None;
 			#endif
 		}
 

Editor/Scripts/IvyEditor.cs

@@ -444,8 +444,9 @@ public override void OnInspectorGUI()
 
                     if ( choice == 0 || choice == 2) {
                         var prefab = AssetDatabase.LoadAssetAtPath<Object>( "Assets" + filename.Substring( Application.dataPath.Length ) );
-                        var newObj = (GameObject)PrefabUtility.InstantiatePrefab( prefab, ivyBehavior.transform );
+                        var newObj = (GameObject)PrefabUtility.InstantiatePrefab( prefab );
                         Undo.RegisterCreatedObjectUndo( newObj, "Hedera > Instantiate OBJ" );
+                        newObj.transform.SetParent( ivyBehavior.transform );
                         newObj.transform.position = ivyGraphObjJob.seedPos;
 
                         var renders = newObj.GetComponentsInChildren<Renderer>();

Editor/Scripts/IvyProfileEditor.cs

@@ -150,10 +150,15 @@ public override void OnInspectorGUI () {
                 content = new GUIContent("Vertex Colors", "Randomize leaf mesh's vertex colors, based on a gradient. Make sure your leaf material's shader supports vertex colors, and the default Hedera foliage shader supports vertex colors. If disabled then no vertex colors will be generated, which saves memory.\n(default: true)");
                 ivyProfile.useVertexColors = EditorGUILayout.Toggle(content, ivyProfile.useVertexColors );
                 if ( ivyProfile.useVertexColors ) {
-                    EditorGUI.indentLevel++;
                     content = new GUIContent("Leaf Colors", "Leaves will pick random vertex colors anywhere along this gradient.\n(default: white > green > yellow)");
+                    #if UNITY_2017_1_OR_NEWER
+                    EditorGUI.indentLevel++;
                     ivyProfile.leafVertexColors = EditorGUILayout.GradientField( content, ivyProfile.leafVertexColors );
-                    EditorGUI.indentLevel--;
+                    EditorGUI.indentLevel--; 
+                    #else
+                    EditorGUILayout.HelpBox("Can't display gradient editor in Unity 5.6 or earlier, for boring reasons. You'll have to edit the gradient in debug inspector.", MessageType.Error);
+                    // ivyProfile.leafVertexColors.colorKeys[0].color = EditorGUILayout.ColorField( content, ivyProfile.leafVertexColors.colorKeys[0].color );
+                    #endif
                 }
 
                 content = new GUIContent("Branch Material", "Unity material to use for branches. It doesn't need to be very high resolution or detailed, unless you set your Branch Thickness to be very wide. Example materials can be found in /Hedera/Runtime/Materials/");