There is a 127 character limit to the filename length (including path) of the HRC degap file. If the filename is > 127 characters, then random memory can get over-written.
The tool copies the PI range from the input file instead of recalculating it. This results in an incorrect subspace value because the SUMAMPS scale (used since CIAO 4.2) extends from 0-1023, while the previously-used PHA scale extends only from 0-255.
Here the mismatch is seen in the column range and the subspace:
unix% dmlist hrc_repro.fits cols | grep "pi " 17 pi chan Int2 0:1023 Pulse Invariant unix% dmlist hrc_repro.fits subspace | grep "pi " 17 pi Int2 0:255