Some Problems Concerning Data File Reading and Composition Model Building in Lammps

Dear Users,
I am using molecular dynamics to study the flow of polymer melts in flats.
Now, I have some difficulties in modeling. I tried to read two data files using the read_data command, but there were always errors.
Details are as follows!
figure1 is my final goal.
figure 2 wall model is generated by wall. data file.
figure 3 fluid model is generated by material studio softwore.
all data file were attached.

I just came into contact with molecular dynamics soon, many of them are not very well understood.
I hope your predecessors can help me, read the wall. data and fluid model. data files through the read_data command in lammps, and finally generate Figure 1.
Thanks in advance

attachments.rar (718 KB)