None of the client are able to register with SCCM 1610 and getting error as below screen shots.
Step 1: Verify random client properties and found Client certificate shows as None.
Step 2: Verified AD level DNS record as showing error on LocationService.log, Found finding records is not available in active directory as client contacting other DNS which no longer active.
Step 3: Go to the client system>Click on run>Type control smscfgrc and enter
You will see Configuration Manager Properties>Click on Site Tab and enter site code which is showing in AD as here example H01 click apply and okay.
Step 4: Wait for while and look the LocationService.log /ClientIDManagerStartup.log you will see client get register as well as client get certificate based on configurations. Here its showing as Self-Signed.
After doing above steps client start reporting to as normal and issue fixed.
Note: You can use ClientActionsTool for multiple system changing site codes.
Email: firstname.lastname@example.org, email@example.com
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