It looks like another administrative operation is currently modifying the ArcGIS Server machine settings, which is preventing you from making changes. This can happen due to:
Concurrent Admin Tasks – Another user or process might be updating the server settings at the same time.
Pending Configuration Updates – A previous administrative operation (like adding/removing a machine or updating properties) may not have completed properly.
Server Machine in Transition State – If the ArcGIS Server machine is restarting or in a transitional state, it might temporarily lock configurations.
Resolution Steps
Wait and Retry – Give it a few minutes and try again. The process may complete on its own.
Check Active Users – Ensure no one else is modifying the settings simultaneously.
Restart ArcGIS Server Service – Restart the ArcGIS Server service from Windows Services or using the services.msc command.
Check Logs – Look at the ArcGIS Server logs (Administrator Directory to Logs) to see if any errors or warnings provide more details.
Restart the Machine – If the issue persists, restarting the server machine may release any locked processes.
Verify Configuration Status – If a machine was recently added or removed, ensure it is properly registered in the ArcGIS Server Site.
If none of these work, you may need to check for stuck administrative operations using the ArcGIS Server REST API or reach out to Esri support for further troubleshooting.
