I don't know what's the template you use.
If you can post your template here, I could propose you an another way to display your comments and md5 hash.
updation by the uploader is not clean.
If you can also say more what does not work as you want.
If you mean the user can not uploaded an *.md5 file ... It's normal. It's for avoid that a .md5 file be replaced by a false *.md5 by a user.
An md5 file can be created when we upload a file, but an file .md5 cannot be uploaded.