I do have this error today while building my container:
installing grafana-clock-panel @ 1.0.3
Installed grafana-clock-panel successfully
Restart grafana after installing plugins .
installing briangann-gauge-panel @ 0.0.6
Error: ✗ failed to download plugin archive: Failed to send request: Api returned invalid status: 500 Internal Server Error
I didn’t have any issue yesterday, do you have some server issue on your end?