If while using Bridge SubD you inadvertently select the Segments bellow 1, the number box displays +∞ and stops responding. Escaping out and running the command again results in the Segments being reset to 1, but the preview of the model showing as though it had zero segments, increasing the Segment count corrects the display issue.
Hello - this appears to be fixed in the latest here - any entry less than 1 is turned into a 1.
I take it back, I see this is Mac and indeed it is a problem there - thanks for the report.
RH-61783 Bridge: Segments less than 1
-Pascal