3dNLfim error


I am trying to use 3dNLfim to fit an exponential curve to some data, but I am coming up against the following error:

*** Error in `/cubric/software/afni.versions/16.2.18/3dNLfim’: munmap_chunk(): invalid pointer: 0x00000000010650c0 ***
======= Backtrace: =========


Fatal Signal 6 (SIGABRT) received
3dNLfim main
Bottom of Debug Stack
** AFNI version = AFNI_16.2.18 Compile date = Sep 19 2016
** [[Precompiled binary linux_openmp_64: Sep 19 2016]]
** Program Death **
** If you report this crash to the AFNI message board,
** please copy the error messages EXACTLY, and give
** the command line you used to run the program, and
** any other information needed to repeat the problem.
** You may later be asked to upload data to help debug.
** Crash log is appended to file /home/sapjw12/.afni.crashlog

I have attached a png file showing the full error message from the .afni.crashlog error.

Does anybody have any ideas?