Could you check if the workflow instance exists at this path? If not, then you should figure out how/when/why was it deleted? In addition to that, you haven't enabled 'handler advance' hence the workflow couldn't proceed and got stuck. I assume that is done on-purpose for a specific requirement?
Try to run the workflow again and monitor ongoing execution & logs to get the next steps.
Could you check if your custom step has completed or stuck and has thrown errors in error.log? Does that second screenshot relate to that error? You'd have to share more details about your use case, implementation and the logs snippets.