error when preview

[youngrichu]

I'm using the latest Adapt authoring tool when i hit preview i get the below error :

Command failed: grunt server-build:prod --outputdir=courses\60fea49cb40f4d62785a366d\61029fde14733e4aec14ded3\build --theme=60fea584b40f4d62785a3688 --menu=adapt-contrib-boxMenu
NameError: variable @primary-color is undefined in src/components/adapt-stacklist/less/stacklist.less on line 10, column 20:
9 	margin-bottom: @item-margin;
10 	background-color: @primary-color;
11 	color: @primary-color-inverted;


Fatal error: NameError: variable @primary-color is undefined in src/components/adapt-stacklist/less/stacklist.less on line 10, column 20:
9 	margin-bottom: @item-margin;
10 	background-color: @primary-color;
11 	color: @primary-color-inverted;
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