Is that in Instant Mode? Or with a controller?
What is the channel selected/configured and what channel width?
What are the configured ARM settings for the channel selection?
My interpretation of the message is that the AP tries to select a 160MHz channel (which you probably should have disabled, especially outdoor) and can't find a an available 160MHz block around channel 48. I think if you limit the 5GHz radio to 40MHz or 20MHz, the message may be gone.
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Herman Robers
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If you have urgent issues, always contact your Aruba partner, distributor, or Aruba TAC Support. Check
https://www.arubanetworks.com/support-services/contact-support/ for how to contact Aruba TAC. Any opinions expressed here are solely my own and not necessarily that of Hewlett Packard Enterprise or Aruba Networks.
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