If the last tangent is already 75 feet long, and thus the VPI is currently located at Sta. 1021+50 and that's not working, then chalk it up to bad software processing and write up a bug report. (I might do this someday, as I've seen some similarly strange things myself.)
As a workaround, I'd extend the last tangent to maybe 75.0001 feet or whatever, until it works. That's about all there is to it, I think.
As a workaround, I'd extend the last tangent to maybe 75.0001 feet or whatever, until it works. That's about all there is to it, I think.