Dashes Tool in After Effects

Hi everyone! Im currently trying to use the "dashes" tool in my shape layer in after effects to create dashes in a circle. For some reason it is not letting me use it, the "+" and "-" icon are not visible. Ive tried reseting my workspace and backtracking any changes ive made but have not yet come up with a solution, does anybody know how to fix this? Any help I can get would be greatly appreciated!s anybody know how to fix this? any help I can get would be greatly appreciated!