How to close tab of child browser

i have a while loop with condition looping till 250 and incrementing by 1,under that there is a body>>Sequence>>Navigate to which then Attachbrowser where i have defined a Output>>Uibrowser variable browser2 as shown in screenshot

,now i have passed this browser2 variable to “Close tab” as shown ![3|690x343] but still main tab is closed instead of child tab,why so?

Have you checked why you have an error “Close Tab: Cannot communicate with Internet Explorer browser” when it looks like you are using chrome as shown in the attach to browser?