WebfontLoader inactive Internet Explorer Custom fonts -


i've done lot of research google's webfontloader , i'm running nuanced issue when loading custom font. i'm trying use events (active/inactive) of webfontloader detect whether font downloads have been disabled. seems work on ie google fonts (like tangerine), shows active when font download enabled , inactive when font download disabled. however, when try load custom font, results in chrome , firefox (can correctly identify if font loaded) internet explorer 11 says inactive custom font (failed load) regardless of whether font download enabled or not (says failed when iconfont loads).

does know why ie 11 return inactive iconfonts? not believe changing teststrings resolve issue (as have seen others have done in other posts).