Cannot choose a 4D datafile for FEAT gui when using HPC

I am trying to use the fsl FEAT GUI to do a level-1 analysis on a High Performance Computing Cluster (HPC). When I try to use the “select 4D data” tab to select an input file (fmri preprocessed nifti file), nothing is selected and I get the following error:

child process exited abnormally
child process exited abnormally
while executing
"exec sh -c “${FSLDIR}/bin/fslnvols $thefile 2> /dev/null” "

  • (procedure “feat5:updateimageinfo” line 9)*
  • invoked from within*
    “feat5:updateimageinfo $w $i 1”
  • (procedure “feat5:multiple_check” line 63)*
  • invoked from within*
    “feat5:multiple_check .r 0 1 1 d”
  • invoked from within*
    “.dialog1.cancel invoke”
  • (“uplevel” body line 1)*
  • invoked from within*
    “uplevel #0 [list $w invoke]”
  • (procedure “tk::ButtonUp” line 22)*
  • invoked from within*
    “tk::ButtonUp .dialog1.cancel”
    (command bound to event)*

also, when I activate the singularity fsl image with the singularity run command, I get the following message: “/usr/share/lmod/lmod/libexec/lmod: No such file or directory” (although it doesn’t prevent me from opening the GUI, so I don’t know if it is related).

Does anyone have an idea why this is happening?

Any help will be highly appreciated.