Digilent bNEXYS 4 DDR is not working. Open Hardware Manager and Open Target are enable but Program Device is disable

[mabidurr]

Hi, 
I am new here. Currently facing problem to connect Digilent bNEXYS 4 DDR with vivado. It is very simple program:

module test_sw_led(SW, LED

);
input [15:0] SW;
output [15:0] LED;

assign LED = SW;

endmodule

Then I tried setting different way. My Synthesis, Run Implementation, Generate BITSTREAM are okay,  After that I am clicking Open Hardware Manager, then Open Target, Auto Connect. It shows connected but enable "Program Device". So I can't proceed next steps. I have tried Project Part different option but I can't solve it. 

Would you please help me?

Regards,

Abid

[hj]

Please make sure you have installed the drivers. Refer to the UG973 for drivers installation. Page#36-37 https://www.xilinx.com/support/documentation/sw_manuals/xilinx2018_3/ug973-vivado-release-notes-install-license.pdf