Error save ad hoc view as xlsx etc..

I've Jaspersoft Server Pro 5.5.0 running and have a problem with saving the result of an ad hoc view as X. When running the ad hoc view as superuser I can save the result as eg xlsx, but when running the ad hoc view as an user and save the result as eg xlsx an error message appears: 

Error Message

java.lang.RuntimeException: An error occurred while performing the previous request..............

All users have read/write permissions on the ad hoc view. What am I missing or is this a bug?

Thnx Remco