diff -ur voms-clients-3.0.5.orig/src/main/java/org/italiangrid/voms/clients/impl/DefaultVOMSProxyInitBehaviour.java voms-clients-3.0.5/src/main/java/org/italiangrid/voms/clients/impl/DefaultVOMSProxyInitBehaviour.java
--- voms-clients-3.0.5.orig/src/main/java/org/italiangrid/voms/clients/impl/DefaultVOMSProxyInitBehaviour.java	2014-10-14 16:38:46.000000000 +0200
+++ voms-clients-3.0.5/src/main/java/org/italiangrid/voms/clients/impl/DefaultVOMSProxyInitBehaviour.java	2014-11-18 11:04:48.080539288 +0100
@@ -439,7 +439,11 @@
 			limitProxy(proxyOptions);
 		
 		if (acs != null && !acs.isEmpty())
-			proxyOptions.setAttributeCertificates(acs.toArray(new AttributeCertificate[acs.size()]));
+			try {
+				proxyOptions.setAttributeCertificates(acs.toArray(new AttributeCertificate[acs.size()]));
+			} catch (IOException e) {
+				throw new VOMSError(e.getMessage(),e);
+			}
 		
 		try {