Interpreting 3Dflex mesh error message

I got an error when I am the 3Dflex mesh prep step:

What does this error message mean?
Let me know if you need the job report for debugging.

Hi @wxh180,
Thanks for reporting. This probably means there’s something different about your .seg file than expected. Are you sure you grouped together the segments in Segger before saving the .seg file?

Posting here in case this is useful for others who have a similar issue:

@wxh180 thanks for sending the .seg file.
The file is not corrupt but it looks like you have one segment in the segmentation that was not grouped.
The final segments that are defined in the file are:
[74, 294, 296, 297, 298, 299, 304]

Segment 74 is a “base” segment (i.e. it’s the smallest region in the segmentation, not grouped with any other regions) but the others 294-304 are all larger groups. Could it be that you meant to group the segments into just 6 parts (294-304) but you missed one small region 74 from the grouping?

Currently our reading of .seg files has a limitation that every final region must be a group rather than a base segment. So if you group segment 74 into one of the larger groups the file will work.
This limitation will be fixed in a future release.

@apunjani Thanks for the explanation! Now it works after grouping 74 with another segment.

PS: do you have a recommendation for the lower boundary (voxel size) for segmentation?