Weird Windows Icon Web Font Display Bug

Problem Setting # Web fonts can not be decoded, pages are showing a lot of squares. For instance, chrome gives following error in concole: Failed to decode downloaded font: https://xxxx.ttf Failed to decode downloaded font: https://xxxx.woff Desktop applications which used web fonts for UI also have display problems: Double click .ttf or try to copy to Fonts folder will give system error: the request file is not a valid font file ...