cannot open old IRAM fits image

[acdo2002]

Describe the bug
Cannot open the old IRAM PdBI fits image

To Reproduce
Steps to reproduce the behavior:

1. Open "n7469-co2.fits" or open "n7469-hcn.fits (link)
   please do not distribute these images to other public places

Expected behavior
Should show the header, however there is no information from the ICD message:
"Error loading headers or image."
Following is the header

SIMPLE = T / SIMPLE FITS FORMAT
BITPIX = 16
NAXIS = 3
NAXIS1 = 129
NAXIS2 = 129
NAXIS3 = 32
BLOCKED = T / TAPE MAY BE BLOCKED
CDELT1 = -5.555555897557E-05 / PRIMARY PIXEL SEPARATION
CROTA1 = 0.000000000000E+00 / PRIMARY ROTATION OF AXIS
CRPIX1 = 6.500000000000E+01 / PRIMARY REFERENCE PIXEL
CRVAL1 = 3.458150000000E+02 / PRIMARY REFERENCE VALUE
CTYPE1 = 'RA---ARC ' / PRIMARY AXIS NAME
CUNIT1 = 'DEGREE ' / PRIMARY AXIS UNITS
CDELT2 = 5.555555897557E-05 / PRIMARY PIXEL SEPARATION
CROTA2 = 0.000000000000E+00 / PRIMARY ROTATION OF AXIS
CRPIX2 = 6.500000000000E+01 / PRIMARY REFERENCE PIXEL
CRVAL2 = 8.873888888889E+00 / PRIMARY REFERENCE VALUE
CTYPE2 = 'DEC--ARC ' / PRIMARY AXIS NAME
CUNIT2 = 'DEGREE ' / PRIMARY AXIS UNITS
CDELT3 = 2.000000000000E+01 / PRIMARY PIXEL SEPARATION
CROTA3 = 0.000000000000E+00 / PRIMARY ROTATION OF AXIS
CRPIX3 = 1.637500000000E+01 / PRIMARY REFERENCE PIXEL
CRVAL3 = 0.000000000000E+00 / PRIMARY REFERENCE VALUE
CTYPE3 = 'VELO ' / PRIMARY AXIS NAME
CUNIT3 = 'KM/S ' / PRIMARY AXIS UNITS
EPOCH = 2.000000000000E+03 / EPOCH
INSTRUME= 'PDBI ' / INSTRUMENT
BLANK = -32768 / TAPE VALUE FOR UNDEFINED PIXELS
BSCALE = 4.589633e-06
BZERO = 0.09871618
DATAMAX = 2.490313E-01 / MAXIMUM DATA VALUE
DATAMIN = -5.160348E-02 / MINIMUM DATA VALUE
ORIGIN = 'WFITS VERSION 1.3' / VERSION OF THE GIPSY PROGRAM
OBJECT = 'NGC7469 ' /
BUNIT = 'Jy/beam ' /
DATE = '05/03/97' / Date written
DEC = .8873888888889E+01 / Declination
RA = .3458150000000E+03 / Right Ascension
END

Platform info (please complete the following information):

• OS [e.g. macOS Monterey]: macOS 13 M1
• Browser [e.g. chrome, safari, electron app]: google
• Browser version [e.g. 22]: Version 114.0.5735.198 (Official Build) (arm64)
• Backend branch [e.g. dev, v3b2 release]: dev & release 4
• Frontend branch [e.g. dev, v3b2 release]: dev & release 4

[kswang1029]

Error loading file: Unit::check Illegal unit string 'DEGREE'