diff --git a/src/main/java/org/gcube/data_catalogue/grsf_publish_ws/ex/ApplicationException.java b/src/main/java/org/gcube/data_catalogue/grsf_publish_ws/ex/ApplicationException.java
index 0e5501d..ae5a2c5 100644
--- a/src/main/java/org/gcube/data_catalogue/grsf_publish_ws/ex/ApplicationException.java
+++ b/src/main/java/org/gcube/data_catalogue/grsf_publish_ws/ex/ApplicationException.java
@@ -21,7 +21,7 @@ public class ApplicationException implements ExceptionMapper<Exception> {
         return Response
                 .status(Response.Status.INTERNAL_SERVER_ERROR.getStatusCode())
                 .type(MediaType.APPLICATION_JSON)
-                .entity(e.getMessage())
+                .entity("{\"error\":" + "\"" + e.getMessage() + "\"}")
                 .build();
     }
 }
\ No newline at end of file
diff --git a/src/main/java/org/gcube/data_catalogue/grsf_publish_ws/ex/ValidationException.java b/src/main/java/org/gcube/data_catalogue/grsf_publish_ws/ex/ValidationException.java
index 64ae890..8a882bf 100644
--- a/src/main/java/org/gcube/data_catalogue/grsf_publish_ws/ex/ValidationException.java
+++ b/src/main/java/org/gcube/data_catalogue/grsf_publish_ws/ex/ValidationException.java
@@ -21,13 +21,14 @@ public class ValidationException implements ExceptionMapper<javax.validation.Val
 	public Response toResponse(javax.validation.ValidationException e) {
 		final StringBuilder strBuilder = new StringBuilder();
 		for (ConstraintViolation<?> cv : ((ConstraintViolationException) e).getConstraintViolations()) {
-			strBuilder.append(cv.getPropertyPath().toString() + " " + cv.getMessage());
+			strBuilder.append(cv.getMessage());
+			break;
 		}
 		logger.warn("ValidationException invoked, returning " + strBuilder.toString());
 		return Response
 				.status(Response.Status.INTERNAL_SERVER_ERROR.getStatusCode())
 				.type(MediaType.APPLICATION_JSON)
-				.entity(strBuilder.toString())
+				.entity("{\"error\":" + "\"" +  strBuilder.toString() + "\"}")
 				.build();
 	}
 }
\ No newline at end of file