The Remote Party Closed The WebSocket Connection Without Completing The Close Handshake

Resolution for UiPath OnPrem Orchestration issue " (error code - 500) in virtual machine " .

Typically, there are two main reasons for the server to cut the connection.

  1. The buffer overflow on the server-side. It could be from the network bandwidth or the application is a slow consumer. If the application subscribes to a lot of items and the update rate is higher than the rate that the application can handle, the server can cut the connection due to the overflow condition. To avoid this issue, the application must process the retrieved message as fast as possible.
  1. The ping timeout on the server. The server will regularly send heartbeat messages (ping messages) every 20 seconds. The application must send pong messages back to the server when receiving ping messages. If the server does not receive any messages from the application for three consecutive ping messages, the server will cut the connection.

  1. Verify if the websocket protocol is enabled on the server or machine.

Read more on the IIS Express Support .