diff --git a/src/main/java/eu/dnetlib/repo/manager/service/ValidatorServiceImpl.java b/src/main/java/eu/dnetlib/repo/manager/service/ValidatorServiceImpl.java
index d516c27..c738846 100644
--- a/src/main/java/eu/dnetlib/repo/manager/service/ValidatorServiceImpl.java
+++ b/src/main/java/eu/dnetlib/repo/manager/service/ValidatorServiceImpl.java
@@ -135,7 +135,7 @@ public class ValidatorServiceImpl implements ValidatorService {
             /////////////////////////////////////////////////////////////////////////////////////////
             // FIXME: this is a hack for CRIS Jan Dvorak Validator, should be implemented properly //
             /////////////////////////////////////////////////////////////////////////////////////////
-            if (jobForValidation.getSelectedContentRules().size() == 1 &&
+            if (jobForValidation.getSelectedContentRules()!=null && jobForValidation.getSelectedContentRules().size() == 1 &&
                     jobForValidation.getSelectedContentRules().contains(-1000)) {
                 crisValidatorExecutor.submit(jobForValidation.getBaseUrl(), jobForValidation.getUserEmail());
             } else {