Problems: Wireless USB card with Atheros AR9271 version 5.21

Hello Everyone.

I have been testing a Wireless USB card with Atheros AR9271 (TP-Link WN722N). It works fine on RB751 with RouterOS version 5.20.

When I updated to version 5.21 some problems started. I can’t manage the wireless interface using WinBox. This message always appears: “Couldn’t change interface <wlan2_wan> - bad on-fail-retry-time (6)”

I am able to manage the wireless interface using console.

Here are some images.

I tried to use version 6RC2 but I can´t see the interface, it does not comes up, but I can see it at system resources.

Any suggestions?

Thanks in advance. Regards.

Please send that message, along with a supout file, to support@mikrotik.com so they can fix it.