diff -r af4693956263 -r e8c0da59391a src/org/gege/caldavsyncadapter/android/entities/AndroidEvent.java
--- a/src/org/gege/caldavsyncadapter/android/entities/AndroidEvent.java	Sat Feb 14 00:28:10 2015 +0100
+++ b/src/org/gege/caldavsyncadapter/android/entities/AndroidEvent.java	Sat Feb 14 00:30:34 2015 +0100
@@ -72,6 +72,8 @@
 import java.net.URISyntaxException;
 import java.text.ParseException;
 
+import static org.junit.Assert.*;
+
 import com.europalab.caldavsyn.Appctxpro;
 
 //import android.accounts.Account;
@@ -319,9 +321,12 @@
     public boolean createIcs(String strUid) {
         boolean Result = false;
         TimeZone timeZone = null;
-        //Thread.currentThread().setContextClassLoader(Context.getApplicationContext().getClassLoader());
-        Thread.currentThread().setContextClassLoader(Appctxpro.getContext().getClassLoader());
-        TimeZoneRegistry registry = TimeZoneRegistryFactory.getInstance().createRegistry();
+        // Hack to bootstrap a multithreaded class loader context
+        if (Thread.currentThread().getContextClassLoader() == null)
+            Thread.currentThread().setContextClassLoader(Appctxpro.getContext().getClassLoader());
+        TimeZoneRegistry registry = TimeZoneRegistryFactory.getInstance();
+        assertNotNull(registry);
+        registry.createRegistry();
 //TODO: do not simply create the ics-file new. take into account the RAWDATA if available
 		/* 
 		 * dtstart=1365598800000