I have created 3 Crosstabs at 3 different Group levels and all work fine up to a point. We use a Parameter in Main report to control Language and number formats, this work fine in main report. Paramter in main report = LanguageCode which for UK is "en_GB". I have set $P{REPORT_PARAMETERS_MAP} in Paramter Map Expression in CT properties. When I try to create a Parameter in CT defualt name is Parameter1, however, properties dialog box will not accept new name of LanguageCode. If I try to override in Advanced Tab I get error Java.lang.NullPointerException. I can not delete Parameter1 either If I use the Code Value in my Format expression all works fine. I can not even add Paramter1 to expression as it does not appear in the object list in the expression edit window. If I manually type $P{Paramter1} the expression errors. If I try to create another Paramter the Parameters list in Outline window does not change, ie Parameter2 does not show in window, but if I now go back to Expression editor a parmeter with name Paramter1 is available, If I add Parameter with default value set as en_GB expression returns Null. Is there a setting I have missed? Thank you Ian