Abort trap: 6 when converting file-type

[JSHuisman]

Dear Harvest developers,

I am trying to use your software to convert an xmfa file into a multi-fasta, using
harvesttools -x ${samplename}.xmfa -M ${samplename}.fasta
But it throws an error:
libc++abi.dylib: terminating with uncaught exception of type std::length_error: basic_string
Abort trap: 6

My best guess is that there must be something wrong with the input-file specification. However, it is possible to load the xmfa into the mauve viewer without any problems; and also when eyeballing the file itself nothing seems wrong.
I am working on MacOS 10.13.6 with 16 Gb of memory.

Do you know what might be causing this error, how I can diagnose it further, or how I could resolve it? Any help would be greatly appreciated!

[swelbo]

same error