"wash -i wlan1mon" ERROR: Could not filter packets - how to fix it?

Hi,

I have TL-WN722N USB adapter with AR9271 driver and when I want to let it be in monitor mode by "airmon-ng start wlan1" and then use wash to see which networks around are WPS locekd by "wash -i wlan1mon" it retrives something like "ERROR: Could not filter packets". It's getting a bit more weired when I type "airmon-ng stop wlan1mon" - "...device is not in monitor mode" while I can see it should be when typed airmon-ng.
Does somebody know whats wrong with that?
Thanks a lot.

Note I did not kill NetworkManager process.

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Note I did not kill NetworkManager process.

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You answered yourself to your problem... ;)

OK, I terminated all processes and got this msg: "ERROR: Could not open "wlan1mon" for capturing". While I can see my USB adapter is in monitor mode and the name is correct.
If I turn on the adapter I get "ERROR: Failed to compile packet filter".