When you find that the integration unit is showing yellow exclamation mark like the picture shows, you may try the following resolution
1. right click over the Virtual Unit and then select mark as repaired.
2. the root cause may be IIS health check. In practice, this means that component is OK, but because health check is not working, HAC shows near failure status. So you may try to disable the health check. (IA -> HAC Level -> intergrations VU -> xyz_integrations -> HTTP monitor -> status and health monitoring -> disable option get status and health from HTTP response)
3. also one option is that there is no chat server installed and that causes integration VU to shwo near failure. We need to install chat server.