In Microstation V8i, you can use the "Extend Line" tool to extend a line to length of zero (start point = end point). In Microstation CE (Update 13.1), when I use the "Extend Line" tool and snap to the start point and accept, nothing happens. The command is ignored. Out of curiosity, I did a fence-stretch of a line, and was able to reduce it to zero length.
Is there any reason that the Extend Line tool in Microstation CE does not allow zero length lines, like the function in V8i?