IOS X Safari favorites icons giving 404 errors

Question

My icons are showing on all other browsers except IOS 10 with Safari when adding to bookmarks/favourites, cannot figure out what is missing or out of place and no help on the forums or documentation. Could someone perhaps tell me the default path used by Safari in IOS 10 to add icons to favorites?

This is my code:

<link rel="apple-touch-icon-precomposed" href="http://www.mainboard.com/apple-touch-icon-precomposed.png" />
<link rel="apple-touch-icon-precomposed" sizes="57x57" href="http://www.mainboard.com/apple-touch-icon-57x57.png" />
<link rel="apple-touch-icon-precomposed" sizes="60x60" href="http://www.mainboard.com/apple-touch-icon-60x60.png" />
<link rel="apple-touch-icon-precomposed" sizes="72x72" href="http://www.mainboard.com/apple-touch-icon-72x72.png" />
<link rel="apple-touch-icon-precomposed" sizes="76x76" href="http://www.mainboard.com/apple-touch-icon-76x76.png" />
<link rel="apple-touch-icon-precomposed" sizes="114x114" href="http://www.mainboard.com/apple-touch-icon-114x114.png" />
<link rel="apple-touch-icon-precomposed" sizes="120x120" href="http://www.mainboard.com/apple-touch-icon-120x120.png" />
<link rel="apple-touch-icon-precomposed" sizes="144x144" href="http://www.mainboard.com/apple-touch-icon-144x144.png" />
<link rel="apple-touch-icon-precomposed" sizes="152x152" href="http://www.mainboard.com/apple-touch-icon-152x152.png" />
<link rel="apple-touch-icon-precomposed" sizes="180x180" href="http://www.mainboard.com/apple-touch-icon-180x180.png">
<link rel="icon" type="image/png" href="http://www.mainboard.com/favicon-16x16.png" sizes="16x16" />
<link rel="icon" type="image/png" href="http://www.mainboard.com/favicon-32x32.png" sizes="32x32" />
<link rel="icon" type="image/png" href="http://www.mainboard.com/favicon-96x96.png" sizes="96x96" />
<link rel="icon" type="image/png" href="http://www.mainboard.com/favicon-128.png" sizes="128x128" />
<link rel="icon" type="image/png" href="http://www.mainboard.com/android-chrome-192x192.png" sizes="192x192">
<link rel="icon" type="image/png" href="http://www.mainboard.com/favicon-196x196.png" sizes="196x196" />
<meta name="application-name" content="MAINBOARD"/>
<meta name="msapplication-TileImage" content="http://www.mainboard.com/mstile-144x144.png" />
<meta name="msapplication-square70x70logo" content="http://www.mainboard.com/mstile-70x70.png" />
<meta name="msapplication-square150x150logo" content="http://www.mainboard.com/mstile-150x150.png" />
<meta name="msapplication-wide310x150logo" content="http://www.mainboard.comm/stile-310x150.png" />
<meta name="msapplication-square310x310logo" content="http://www.mainboard.com/mstile-310x310.png" />
<link rel="manifest" href="http://www.mainboard.com/manifest.json">
<link rel="mask-icon" href="http://www.mainboard.com/safari-pinned-tab.svg" color="#fff">
<meta name="msapplication-TileColor" content="#da532c">
<meta name="msapplication-TileImage" content="http://www.mainboard.com/mstile-144x144.png">
<meta name="theme-color" content="#ffffff">

Answer 1

I suggest you to submit your site to the favicon checker. If will check your markups and icons. At the time of writing this answer, it is full green. So you can be nearly sure that everything is alright. Full disclosure: I'm the author of this service.

Keep in mind that browsers tend to be very lazy regarding favicon. For example, favicon caching is a recurrent web development issue. In the case of iOS Safari, I often observed that Safari does not always load the icon on time while bookmarking. Consequence: while testing your touch icon, you have the feeling that it does not work. It actually works, but you have to try again a minute later. Frustrating. Another possible issue is that, as the site author, you are constantly visiting your site under development. Maybe Safari considers your touch icon is broken (maybe it was at some point: this is a site under dev after all) so it does not reload it, but will eventually do it... later.

My advice here is to try with another iOS device if you have one at your disposal.