Slic3r problems

After attempting to move an object manually on the object layout before slicing to get the G-code, I receive the following error messages:
"Slic3r exited with error."
and
"12:29:05 PM: <Slic3r> Can't call method "clone" on unblessed reference at /Volumes/Repetier-Host Mac.app/Repetier-Host Mac.app/Contents/Resources/Slic3r.app/Contents/Resources/lib/std/Slic3r/Print.pm line 157."

If anyone has any ideas, please let me know. We have tried disconnecting, restarting, closing Repetier and reopening it, reconnecting and trying to 'slice' again to no avail. We also checked various settings and nothing seems to be amiss.

 

my husband just realized that he selected "complete individual objects" before trying to move the objects; deselecting it fixed the problem.