[unity] Fixed a potential null reference exception, potentially leading to failing drag and drop instantiation.

spine-unity/Assets/Spine/Editor/spine-unity/Editor/Utility/BlendModeMaterialsUtility.cs

@@ -207,6 +207,18 @@ namespace Spine.Unity.Editor {
 			if (File.Exists(blendMaterialPath)) {
 				newReplacement.material = AssetDatabase.LoadAssetAtPath<Material>(blendMaterialPath);
 			} else {
+				if (materialTemplate == null) {
+					Debug.LogError(string.Format("Failed to create blend mode material: Material template for " +
+						"blend mode '{0}' was null. Re-importing might fix this issue.",
+						materialSuffix), originalMaterial);
+					return null;
+				}
+				if (originalMaterial == null) {
+					Debug.LogError(string.Format("Failed to create blend mode material for atlas page '{0}': Original material for " +
+						"blend mode '{1}' was null. Re-importing might fix this issue.",
+						originalPage.name, materialSuffix));
+					return null;
+				}
 				Material blendModeMaterial = new Material(materialTemplate) {
 					name = originalMaterial.name + " " + materialTemplate.name,
 					mainTexture = originalMaterial.mainTexture

spine-unity/Assets/Spine/package.json

@@ -2,7 +2,7 @@
 	"name": "com.esotericsoftware.spine.spine-unity",
 	"displayName": "spine-unity Runtime",
 	"description": "This plugin provides the spine-unity runtime core.",
-	"version": "4.2.85",
+	"version": "4.2.86",
 	"unity": "2018.3",
 	"author": {
 		"name": "Esoteric Software",