Forum Discussion
ATP connectivity challenge HTTP Error 400
Hi, I am trying to onboard an ATP client on Windows 10 using SCCM.
SCCM states the policy was applied correctly. The ATP service is running, the sense logs only contains warning and error messa...
Same issue here, I get lots of the following errors in the SENSE event logs.
Contacted server 58 times, all failed, URI: https://winatp-gw-eus.microsoft.com/. Last HTTP error code: 400
Have you had any luck from support?
My issue was resolved by offboarding from a different tenant and onboard subsequently.
Even if you reset the device, if it has been part of a previous poc on atp the onboarding will fail.
and if we can't remember the tenant that we used before to login and get the offboarding script I assume there is nothing else we can do?
Support was looking at creating an offboarding script based on data found in the registry. There wasn't an easy way to create that ourselves. I managed to find my tenant back and eventhough it had long expired I could still log into it and download an offboarding script. If you still know what mailbox the poc was requested in you might find the mail with your login. It should contain this string Analyst@Windows.
Good luck
