Standalone ModRefiner can not open a PDB file

Hi everyone

I modeled my protein on I TASSER and then tried to refine it on the modrefiner right on the desktop (the web version is unavailable). However, I get the following message: "PDB file can not be opened" (in this case, the protein I just modeled). Has anyone had a similar problem, and if so, any suggestions on how to resolve it? Both structures (the model and the template) are in PDB format. The command line I used was the same as indicated in the program's documentation. (./mcrefinement data_dir bin_dir ini_name ref_name ran_num)

Best regards