variable @fa-css-prefix is undefined on line 7 in file '/Content/icons/fontawesome-5.3.1/less/_larger.less':
  [6]: 
  [7]:   .@{fa-css-prefix}-@{factor}x {
       ---^
  [8]:     font-size: (@factor * 1em);
from line 27:
 [27]: .larger(10);