Neptune Graph Explorer responding with status 500

Hello and thanks for posting. We are currently investigating why this issue happens but it is typically a result of the SageMaker instance upon which the notebook and Graph Explorer reside having undergone some maintenance actions. Simply restarting (stop followed by start) the SageMaker notebook instance should resolve the issue. Please note that during a restart some of the Graph Explorer and Graph Notebook software may be updated. As part of that the sample notebooks included with the Graph Notebook will get replaced with the latest ones. If you have made any edits to those sample notebooks that you wish to keep please make backup copies before restarting the SageMaker instance. You can do the restart from either the Neptune or SageMaker AWS Web console. After the restart the HTTP 500 issue should go away. We are investigating ways to prevent this from happening but in the meantime hopefully that gets you going again.

UPDATED 2023-01-10

Adding an update to mention that a new version of Graph Explorer was just released this week (version 1.5.0). Restarting the instance again should pick up this new version. There are several fixes in the new release that should help in the area of graph synchronization.