FT-4XR, 4/29/2019 version of CHIRP
Note that the receive range for all versions of this radio is 65-108 MHz, 136-174 MHz, and 400-480 MHz. This build seems to only accommodate receive (and transmit) frequencies in the U.S. transmit range (144-148 MHz, 430-450 MHz).
Also, this radio has three versions: Asian, European, and USA. MARS members (like myself) use the Asian version, which transmits 136-174 MHz and 400-480 MHz. It would be nice if transmit frequencies for any of the three versions could be accommodated in CHIRP.
The following Yaesu link (numbered page 30, PDF page 32) shows the frequency ranges of the various versions of this radio: http://www.yaesu.com/downloadFile.cfm?FileID=14688&FileCatID=151&FileName=FT%2D4XR%5FXE%5FOM%5FENG%5FEH069M201%5F1805M%2DBC.pdf&FileContentType=application%2Fpdf
Updated by David Behar over 4 years ago
I had marked this issue as a "Feature", but I suppose it could also be considered a bug. In the olden days, we used to always say "it's not a bug, it's a feature!"
Separately, as a temporary work-around I find that I can prepare a CSV file with the desired frequencies (outside the U.S. amateur allocations), and then import the CSV file.
This YouTube video shows how to unlock a radio for testing (or for use if you are authorized, e.g., MARS members): https://www.youtube.com/watch?v=vPnmmz3xjbc