Invalid Curve Error

Hi! I am experiencing an “Operation would result in an invalid curve” error. The logo in the attached screenshot is broken up into 4 sections. I was looking to use the Offset Edge (loop) tool on the outer frame of the top right section but am getting the error. I did not get that error when I performed the same task on the other 3 sections. How can I troubleshoot this problem? I did try to isolate the shape by selecting individual edges and using the Offset Edge (single) but some of the edges would not allow me to select them. Anyone have any solutions?