Hi I am a beginner to Galaxy and have decided to use it to detect SNP in the miRNA of different viral disorders. The work flow that I am using is Get data -> fastQC -> Trimmomatic -> bowtie2 -> sort -> rmdup -> mpileup -> SNPEFF

The problem here is , in my SNP eff results the entire column seems to zero and the preceding column is just "*" What should be my interpretation here ? Have I done anything wrong ? Pls clarify