To start with, when installing AutoPIPE Vessel, the program will install a small app called CONNECTION Client. This is a Bentley Application and must be signed into, see WIKI here. You can open this application by locating the icon in your task bar, right clicking on it, and select OPEN. This application uses the same credentials when logging into Bentley.com or Communities website.

Once opened, you can perform many tasks, one of which is to open the CONNECTION Center. This is a Website for collaborative purposes, training, etc...   

This message that appears is not related to any Bentley application. If you look at the title of the message bar, it references an application called HpCONNECTIONMANAGER. exe. From a simple google search one would be able to find a list of results,google search here

HP PCs - HP Connection Manager Fatal Error - https://support.hp.com/us-en/document/c05074618

Suggest that you contact HP technical support for assistance in why this window is appearing. Aside from that, if you have any virus protection on the computer be sure to add all AutoPIPE Vessel folders, application *.exe, and file type as a trusted source / exception.