Hi, I'm working with 777bp nucleotide sequence which one protein region from virus. I have sequence file approximately 40. I'm testing SLAC, GARD etc. on sequence with HyPhy tools in usegalaxy.org. But SLAC give an error. Any help or suggestion would be highly appreciated.

Error:"The input alignment must have the number of sites that is divisible by 3 and must not contain stop codons in call to assert(fel.codon_filter.sites*3==fel.codon_data.sites, error_msg);"