Its possible that the Open isn't complete when the Select is executed?
I haven't seen this exact problem, but something like it when I'm working with tables that have lots of rows.
Two suggestions:
First, assign the data table to a variable when its opened. This way dt=current data table(); doesn't accidentally end up pointing at the current table, while the database table is opening.
dt=open database("DNS....
Leave out the dt=current data table();
Second, force dt to be evaluated before selecting rows. It can't be evaluated before it finishes opening
dt<<Run Formulas; //include this first
dt<<Select Where(Exclude=="Exclude")<<hide<<Exclude;
JMP Systems Engineer, Health and Life Sciences (Pharma)