My form has a subform that becomes visible when 'yes' is ticked in a radio button group (there are several radio button groups and subforms). The subform appears again on a summary page - I included instances of the hidden subform in two places. I have made each field in the subform 'global' so all data appears the same in both instances of the subform. This worked fine on the first few of these forms. On the latest I received the above message and the form won't open. Can anyone tell me what this message means, and if there is an easy way to find the problem and fix it. Thanks.