I am also getting the "Only a single spinal weapon mount can be added to a design" error.
It happens on game creation. The more starting NPRs, the more error popups, seems to be 1-3 popups per NPR. They also pop up intermittently during construction phases. Maybe 1 or 2 in a year.
Side note. . . I'm using the built in Windows Defender and got no alerts regarding a virus/trojan.
