input file without parts and assemblies

[svenlee]

Hi to everybody
I am new to ABAQUS, I am working on executing a buckling examples in ABAQUS,'snap-through buckling analysis of circular arches'. I use Ab cae. I have download two input files, 'snapbuckling_shallow_step1.inp' and 'snapbuckling_shallow_unload.inp'. I can import fist input file into Ab and finish the calculation, however, when I import the second file into Ab, I got the error message as:
There are no meshes in the model.
Go to the Mesh module and mesh all instances
The input file was not generated, and so the job was not submitted for analysis

I have tried the command: mdb.models[modelName].setValues(noPartsInputFile=ON), useless.
Please help me!

Thank you in advance