Paging is not working in terminal mainframe

Hi,

I have searched in a forum even with the same question I found many solutions too. But any of the solutions are not working. Please help. I fed up. Terminal activity PAgedown is not working and Page down is already mapped in the terminal and manually it is working fine. I changed to Function key “F1” but it is saying that function key is not allowed. Kindly help.

Regards,
Hemal