hi all, is there a way to prevent a grid from showing a default empty row

The grids will be blank as long as none of the values that you set as 'default value' for the columns are all null. It seems that one of your array values is not blank. This is possible if you've set a default value at the Process Variables level or during any of the expression. The best way to test this is to check the values in a running instances using in flight monitoring. This will tell you what data is causing the issue.
The reason for your row is the TRUE FALSE field. Having a value of 'False' indicates to the grid to display the corresponding 'cell' with the value of false (unchecked). Try setting the default value of this pv to null and it should get rid of your row.

thanks , i'll try again tomorrow.

hi srinivasan, i tried it again today.
i found:
in my poc model i set null as default value for boolean input, default empty row disappears.
but in my project model it did not.
and when i created a empty boolean process variable and used it instead of null,
it worked again.