Hi everyone, The following files will throw an error when run with $ pdftex d1.tex. `d1.tex` \nonstopmode \input expl3-generic \relax \ExplSyntaxOn % -*- expl3 -*- \file_input:n { d2 } \bye `d2.tex` \msg_term:n { hello,~world } The log file is attached. Thanks, Sean Allred This is pdfTeX, Version 3.14159265-2.6-1.40.16 (TeX Live 2015) (preloaded format=pdftex 2015.5.24) 3 JUL 2015 18:53 entering extended mode restricted \write18 enabled. %&-line parsing enabled. **d1.tex (./d1.tex (/usr/local/texlive/2015/texmf-dist/tex/latex/l3kernel/expl3-generic.tex Package: expl3 2015/03/01 v5547 L3 programming layer (loader) (/usr/local/texlive/2015/texmf-dist/tex/latex/l3kernel/expl3-code.tex Package: expl3 2015/03/01 v5547 L3 programming layer (code) L3 Module: l3bootstrap 2015/02/28 v5542 L3 Bootstrap code L3 Module: l3names 2015/02/24 v5535 L3 Namespace for primitives L3 Module: l3basics 2015/01/27 v5500 L3 Basic definitions L3 Module: l3expan 2014/11/27 v5472 L3 Argument expansion L3 Module: l3tl 2015/01/27 v5500 L3 Token lists L3 Module: l3str 2015/03/01 v5545 L3 Strings L3 Module: l3seq 2014/08/23 v5354 L3 Sequences and stacks L3 Module: l3int 2015/02/21 v5529 L3 Integers \c_max_int=\count27 \l_tmpa_int=\count28 \l_tmpb_int=\count29 \g_tmpa_int=\count30 \g_tmpb_int=\count31 L3 Module: l3quark 2014/08/23 v5354 L3 Quarks L3 Module: l3prg 2014/08/23 v5354 L3 Control structures \g__prg_map_int=\count32 L3 Module: l3clist 2014/08/23 v5354 L3 Comma separated lists L3 Module: l3token 2014/09/15 v5422 L3 Experimental token manipulation L3 Module: l3prop 2014/08/23 v5354 L3 Property lists L3 Module: l3msg 2015/02/26 v5537 L3 Messages L3 Module: l3file 2014/08/24 v5369 L3 File and I/O operations \l_iow_line_count_int=\count33 \l__iow_target_count_int=\count34 \l__iow_current_line_int=\count35 \l__iow_current_word_int=\count36 \l__iow_current_indentation_int=\count37 L3 Module: l3skip 2014/08/23 v5354 L3 Dimensions and skips \c_zero_dim=\dimen16 \c_max_dim=\dimen17 \l_tmpa_dim=\dimen18 \l_tmpb_dim=\dimen19 \g_tmpa_dim=\dimen20 \g_tmpb_dim=\dimen21 \c_zero_skip=\skip18 \c_max_skip=\skip19 \l_tmpa_skip=\skip20 \l_tmpb_skip=\skip21 \g_tmpa_skip=\skip22 \g_tmpb_skip=\skip23 \c_zero_muskip=\muskip10 \c_max_muskip=\muskip11 \l_tmpa_muskip=\muskip12 \l_tmpb_muskip=\muskip13 \g_tmpa_muskip=\muskip14 \g_tmpb_muskip=\muskip15 L3 Module: l3keys 2015/01/27 v5500 L3 Key-value interfaces \g__keyval_level_int=\count38 \l_keys_choice_int=\count39 L3 Module: l3fp 2014/08/22 v5336 L3 Floating points \c__fp_leading_shift_int=\count40 \c__fp_middle_shift_int=\count41 \c__fp_trailing_shift_int=\count42 \c__fp_big_leading_shift_int=\count43 \c__fp_big_middle_shift_int=\count44 \c__fp_big_trailing_shift_int=\count45 \c__fp_Bigg_leading_shift_int=\count46 \c__fp_Bigg_middle_shift_int=\count47 \c__fp_Bigg_trailing_shift_int=\count48 L3 Module: l3box 2014/08/23 v5354 L3 Experimental boxes \c_empty_box=\box16 \l_tmpa_box=\box17 \l_tmpb_box=\box18 \g_tmpa_box=\box19 \g_tmpb_box=\box20 L3 Module: l3coffins 2014/08/23 v5354 L3 Coffin code layer \l__coffin_internal_box=\box21 \l__coffin_internal_dim=\dimen22 \l__coffin_offset_x_dim=\dimen23 \l__coffin_offset_y_dim=\dimen24 \l__coffin_x_dim=\dimen25 \l__coffin_y_dim=\dimen26 \l__coffin_x_prime_dim=\dimen27 \l__coffin_y_prime_dim=\dimen28 \c_empty_coffin=\box22 \l__coffin_aligned_coffin=\box23 \l__coffin_aligned_internal_coffin=\box24 \l_tmpa_coffin=\box25 \l_tmpb_coffin=\box26 \l__coffin_display_coffin=\box27 \l__coffin_display_coord_coffin=\box28 \l__coffin_display_pole_coffin=\box29 \l__coffin_display_offset_dim=\dimen29 \l__coffin_display_x_dim=\dimen30 \l__coffin_display_y_dim=\dimen31 L3 Module: l3color 2014/08/23 v5354 L3 Experimental color support L3 Module: l3candidates 2015/03/01 v5544 L3 Experimental additions to l3kernel \l__box_top_dim=\dimen32 \l__box_bottom_dim=\dimen33 \l__box_left_dim=\dimen34 \l__box_right_dim=\dimen35 \l__box_top_new_dim=\dimen36 \l__box_bottom_new_dim=\dimen37 \l__box_left_new_dim=\dimen38 \l__box_right_new_dim=\dimen39 \l__box_internal_box=\box30 \l__coffin_bounding_shift_dim=\dimen40 \l__coffin_left_corner_dim=\dimen41 \l__coffin_right_corner_dim=\dimen42 \l__coffin_bottom_corner_dim=\dimen43 \l__coffin_top_corner_dim=\dimen44 \l__coffin_scaled_total_height_dim=\dimen45 \l__coffin_scaled_width_dim=\dimen46 ) (/usr/local/texlive/2015/texmf-dist/tex/latex/l3kernel/l3pdfmode.def File: l3pdfmode.def 2014/10/16 v5435 L3 Experimental driver: PDF mode \l__driver_color_stack_int=\count49 ) (/usr/local/texlive/2015/texmf-dist/tex/latex/l3kernel/l3unicode-data.def File: l3unicode-data.def 2015/03/01 v5544 L3 Unicode data )) \g__file_internal_ior=\read1 ! Undefined control sequence. <argument> \g_file_current_name_tl \exp_args:NNo ...\exp_after:wN #2\exp_after:wN {#3 } \__file_input_aux:n ...eq \g_file_current_name_tl \tl_gset:Nn \g_file_curren... l.5 \file_input:n { d2 } The control sequence at the end of the top line of your error message was never \def'ed. If you have misspelled it (e.g., `\hobx'), type `I' and the correct spelling (e.g., `I\hbox'). Otherwise just continue, and I'll forget about whatever was undefined. (./d2.tex ************************************************* * hello, world ************************************************* ) ) No pages of output. PDF statistics: 0 PDF objects out of 1000 (max. 8388607) 0 named destinations out of 1000 (max. 500000) 1 words of extra memory for PDF output out of 10000 (max. 10000000)