Renamed WEPIFRutimeException to WEPIFRuntimeException and gave it a serialVersionUID.

src/main/java/com/sk89q/wepif/PermissionsResolverManager.java

@@ -69,7 +69,7 @@ public class PermissionsResolverManager implements PermissionsResolver {
 
     public static PermissionsResolverManager getInstance() {
         if (instance == null) {
-            throw new WEPIFRutimeException("WEPIF has not yet been initialized!");
+            throw new WEPIFRuntimeException("WEPIF has not yet been initialized!");
         }
         return instance;
     }

src/main/java/com/sk89q/wepif/WEPIFRuntimeException.java

@@ -0,0 +1,12 @@
+package com.sk89q.wepif;
+
+/**
+ * @author zml2008
+ */
+public class WEPIFRuntimeException extends RuntimeException {
+    private static final long serialVersionUID = 1L;
+
+    public WEPIFRuntimeException(String message) {
+        super(message);
+    }
+}

src/main/java/com/sk89q/wepif/WEPIFRutimeException.java

@@ -1,12 +0,0 @@
-package com.sk89q.wepif;
-
-/**
- * @author zml2008
- */
-public class WEPIFRutimeException extends RuntimeException {
-    
-    public WEPIFRutimeException(String message) {
-        super(message);
-    }
-
-}