Error message while running goatools

[akaur1988]

While running goatools, I get following error message. I am also attaching first 20 lines of my study, population and association file.
Please help me with this.

Thanks
$
20_lines_association.txt
20_lines_population.txt
20_lines_study.txt
study=Gene_list_of_3D_genes.txt
$ population=Mapping_spud.txt
$ association=parsed_GO
$ output=go_annotation_spud_3d
$ obo=go-basic.obo
$ find_enrichment.py --alpha=$alpha --pval=$p_val --indent --obo $obo $study $population $association > $output

WARNING: only 0.0 fraction of genes/proteins in study are found in the population background.

ERROR: only 0.0 of genes/proteins in the study are found in the background population. Please check.