There is no issue with your file formats. They are fine.

Please add a snapshot of the error message so that people could help you.

Yes. It will be more easy to help if you tell what kind of error you are getting.

You should use the PDB file format for the ligand too. This you can do it by using MOE software where you can minimize the energy of the ligand and then save in the PDB format. Minimization can also be done using other software like Gaussian.