Shape files have multiple files with the same name but different extensions that all need to be in the same folder. Usually you have a .shp, .dbf and a .prj file all by the same name in the same folder for the program to properly read and display the shapefile.
I am having an issue too, but it is the following message when I select view -> severe weather zones :
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There are no DBF files containing forecast zone definitions. Download them from https://www.weather.gov/gis/AWIPSShapefFiles and unzip them into your configured YAAC tile directory, then it lists my directory.
I did download and unzip all 3 files, county, zone, and marine into the tiledir.?