An error occurred reading the comsol mphtxt grid file

[czimidone]

In the process of reading a COMSOL Multiphysics file (mphtxt) using GridIn, an error occurs when trying to read the mesh section.
I looked at the source code of "read_comsol_mphtxt function" and didn't find the problem.

The error message states：

An error occurred in line <1557> of file </home/dlut/software/dealii/dealii-9.4.1/source/grid/grid_in.cc> in function
void dealii::GridIn<dim, spacedim>::read_comsol_mphtxt(std::istream&) [with int dim = 2; int spacedim = 2; std::istream = std::basic_istream]
The violated condition was:
s == "4 Mesh"

the start of ”mphtxt“：

            # Created by COMSOL Multiphysics.
            
            # Major & minor version
            0 1 
            1 # number of tags
            # Tags
            5 mesh1 
            1 # number of types
            # Types
            3 obj 
            
            # --------- Object 0 ----------
            
            0 0 1 
            4 Mesh # class
            4 # version
            2 # sdim
            296 # number of mesh vertices
            0 # lowest mesh vertex index

main function：
GridIn grid_in;
grid_in.attach_triangulation(triangulation);
std::ifstream input_file("example.mphtxt");
grid_in.read_comsol_mphtxt(input_file);