I just had that issue, and I compared my IIS10 (win10) and IIS 7.5 (win2008 R2) applicationhost.config files, and these are the changes I sent from iis10 to iis75.
29 new types, and 5 modified.
Watch out for .ts if you use typescript... ts was a video file before being a programming language file
<!-- new types -->
<mimeMap fileExtension=".3g2" mimeType="video/3gpp2" />
<mimeMap fileExtension=".3gp2" mimeType="video/3gpp2" />
<mimeMap fileExtension=".3gp" mimeType="video/3gpp" />
<mimeMap fileExtension=".3gpp" mimeType="video/3gpp" />
<mimeMap fileExtension=".aac" mimeType="audio/aac" />
<mimeMap fileExtension=".adt" mimeType="audio/vnd.dlna.adts" />
<mimeMap fileExtension=".adts" mimeType="audio/vnd.dlna.adts" />
<mimeMap fileExtension=".appcache" mimeType="text/cache-manifest" />
<mimeMap fileExtension=".dvr-ms" mimeType="video/x-ms-dvr" />
<mimeMap fileExtension=".json" mimeType="application/json" />
<mimeMap fileExtension=".jsonld" mimeType="application/ld+json" />
<mimeMap fileExtension=".less" mimeType="text/css" />
<mimeMap fileExtension=".m2ts" mimeType="video/vnd.dlna.mpeg-tts" />
<mimeMap fileExtension=".m4a" mimeType="audio/mp4" />
<mimeMap fileExtension=".m4v" mimeType="video/mp4" />
<mimeMap fileExtension=".mp4" mimeType="video/mp4" />
<mimeMap fileExtension=".mp4v" mimeType="video/mp4" />
<mimeMap fileExtension=".oga" mimeType="audio/ogg" />
<mimeMap fileExtension=".ogg" mimeType="video/ogg" />
<mimeMap fileExtension=".ogv" mimeType="video/ogg" />
<mimeMap fileExtension=".otf" mimeType="font/otf" />
<mimeMap fileExtension=".spx" mimeType="audio/ogg" />
<mimeMap fileExtension=".svgz" mimeType="image/svg+xml" />
<mimeMap fileExtension=".ts" mimeType="video/vnd.dlna.mpeg-tts" />
<mimeMap fileExtension=".tts" mimeType="video/vnd.dlna.mpeg-tts" />
<mimeMap fileExtension=".webm" mimeType="video/webm" />
<mimeMap fileExtension=".woff" mimeType="font/x-woff" />
<mimeMap fileExtension=".woff2" mimeType="application/font-woff2" />
<mimeMap fileExtension=".wtv" mimeType="video/x-ms-wtv" />
<!-- modified types -->
<mimeMap fileExtension=".avi" mimeType="video/avi" />
<mimeMap fileExtension=".cab" mimeType="application/vnd.ms-cab-compressed" />
<mimeMap fileExtension=".eot" mimeType="application/vnd.ms-fontobject" />
<mimeMap fileExtension=".ics" mimeType="text/calendar" />
<mimeMap fileExtension=".js" mimeType="application/javascript" />