Are atom coordinates in molfile necessary to produce a valid InChI identifier
Quoting from &quot;InChI, the IUPAC International Chemical Identifier&quot; article [Heller et al. Journal of Cheminformatics (2015) 7:23]:

Each atom is described by a number of properties: its
chemical element name; x,y,z- coordinates (all or any of
them may be zero);

When I edit all coordinates to zero, inchi-1 produces a valid InChI identifier:
InChI=1S/C7H6O2/c8-7(9)6-4-2-1-3-5-6/h1-5H,(H,8,9)

and auxiliary info, which reflect no valid atom coordinates available:
AuxInfo=1/1/N:6,3,7,1,4,2,5,8,9/E:(2,3)(4,5)(8,9)/rA:9nCCCCCCCOO/rB:d1;s1;s2;s2;d3;d4s6;s5;d5;/rC:;;;;;;;;;

I did a similar test earlier, but I didn't retain the strict 10 character column width for each coordinate, which produced an error:
Error 34 (no InChI; Cannot interpret atom block line:     0.0000  0.0000    0.0000