How could I build more than 2000 POPC bilayer

GROMACS version: 2020.4
GROMACS modification: Yes/No
I’ve tried to build a protein with residue 407 embeded POPC bilayer.
As my protein is lager than POPC128.pdb (from http://wcm.ucalgary.ca/tieleman/downloads), I needed to generate larger POPC membrane.
I added single POPC molecule in popc128.pdb for each leaflet, concatenated protein.gro file and popc.gro file, and used ‘inflategro.pl’ file. But the some unexpected messages are raised as below:


Use of uninitialized value in addition (+) at /home/byun/PROject/APP-complex/GROMOS-ff/GADGET/inflategro.pl line 496.
Use of uninitialized value within @overlap in numeric eq (==) at /home/byun/PROject/APP-complex/GROMOS-ff/GADGET/inflategro.pl line 500.
Argument “A2” isn’t numeric in printf at /home/byun/PROject/APP-complex/GROMOS-ff/GADGET/inflategro.pl line 502.

And inflategro.pl identified the wrong number of popc molecules…
My system has 8126 popc molecules but the verbose message showed There are 3782 lipids...

The figure below is output(system_inflated.gro)

How can I solve this problem?
Thank you for considering my question :)