Problem:
Your cluster fails to start with an error:
InvalidGroup.NotFound. The security group 'sg-XYZ' does not exist in VPC 'vpc-XYZ'
Cause:
The network security group policy is not correctly configured.
Solution:
- Contact your network engineering team to verify the security group policy is correctly associated with the Databricks workspace VPC.
 - Ensure the security group 
sg-XYZexists in the VPCvpc-XYZ. - If the security group does not exist, create it using the appropriate console or API commands.
 - If the security group exists, ensure it is correctly associated with the workspace VPC.
 - If the security group is associated correctly, verify the inbound and outbound rules are configured to allow network traffic for the Databricks cluster.
 - After updating the security group configuration, restart the cluster and verify that it launches correctly.