Your pour command inserts atoms of type 2 (1 from the data file + 1 from an offset in fix pour), while you declared only one type of atoms in the create_box command.
Thanks, I modified the fix pour command like this: fix ins1 all pour 100 0 12345 region slab mol object
“Error: Invalid atom type in fix pour mol command” is solved successfully.
But I meet another error: Fix pour insertion count per timestep is 0 <…/fix_pour.cpp:258>. In fact, this error usually occurs when I use fix pour command. What is lammps telling about?