| DCV tab doesn’t open |
Connection initializing |
Wait a few seconds and try again |
| Certificate warning |
Self-signed certificate |
Click Advanced → Proceed (this is expected) |
| High latency in DCV |
Using TCP in distant region |
Use the native DCV client with UDP |
| UDP not working |
Port 8443 UDP not open |
Open UDP:8443 in the head node security group |
| SSH connection refused |
Cluster not running |
Check cluster status in PCUI |
| SSM shell won’t connect |
IAM policy missing |
Ensure AmazonSSMManagedInstanceCore policy is attached |