Issue in ERRORR with ign=1 (Read in energy grid) option

[suhailak]

I was getting the following error message when I use 172 group WIMS energy group structure as the input energy grid option in ERRORR using ign=1
error in colapsngout group structure does not span union grid.
To resolve this, first I used ign=18 which is inbuilt 172 group xmas group structure. Using this option, the njoy run smoothly completed. I took these energy group boundaries from the output and give the run again with ign=1 option. This time njoy run again terminated with the above error message.
A closer view of the two energy group structures in the output files shows that with ign=1 option, the energy group boundaries are approximated to four significant places after decimal even if more significant digits are present in the input option. This doesn’t happen with inbuilt ign=18 option. The modification to four significant digits has reduced one group from union structure – 839 groups for ign=1 option vs 840 groups for ign=18 option.
Can developers confirm whether is this the reason for above error message? How to solve it?