Merge pull request #181 from Unity-Technologies/UNI-28475-converting-UI-crashes-Unity

UNI-28475 auto connect when creating prefab

Author: inwoods

Assets/FbxExporters/Editor/ConvertToModel.cs

@@ -206,16 +206,13 @@ public static GameObject Convert (
 
                 // Create a prefab from the instantiated and componentized unityGO.
                 var prefabFileName = Path.ChangeExtension(projectRelativePath, ".prefab");
-                var prefab = PrefabUtility.CreatePrefab(prefabFileName, unityGO);
+                var prefab = PrefabUtility.CreatePrefab(prefabFileName, unityGO, ReplacePrefabOptions.ConnectToPrefab);
                 if (!prefab) {
                     throw new System.Exception(
                         string.Format("Failed to create prefab asset in [{0}] from fbx [{1}]",
                             prefabFileName, fbxFullPath));
                 }
 
-                // Connect to the prefab file.
-                unityGO = PrefabUtility.ConnectGameObjectToPrefab(unityGO, prefab);
-
                 // Remove (now redundant) gameobject
                 bool actuallyKeepOriginal;
                 switch(keepOriginal) {