I am having a problem in preparing ligand library. I have followed all the steps but I am afraid the frcmod file is not correct since I get some error which says "ATTN need revision".

I attached the frcmod file too. Besides the error, I prepared library file for ligand and continued with pre-processing steps, prepared the prmtop and inpcrd files followed by the minimisation. But sander stops after 500 steps and gives some error like this VDWAALS= ***** and EEL = ****** . Can anyone please have a look at the attached file & suggest some help?