hi all what can i do to solve this problem?
chipset realtek RTL8187

This is user forum, we can't help you. Your only chance is to ask MikroTik directly (send mail to their support). But don't expect much, they never said it would be their goal to support all existing hardware.

What Mikrotik? Yours device model is Mikrotik? Strange...

this model http://routerboard.com/RB951Ui-2HnD

I believe Mikrotik only supports Qualcomm / Atheros wifi chipsets, no Realtek.

RouterOS only supports chipsets that we use in our RouterBOARD products and Realtek 8187L is not one of them.