If you want to fix error OST file missing Outlook 2016, so here I suggest you t get SysInspire OST to PST converter software. This tool can convert OST file into multiple file format such as OST to PST, EML, EMLX, Office 365, HTML, Yahoo Mail, Gmail, etc. It has a demo version that can allow users to convert 25 items from each folders. It has a technical support all users can get help by mail or live chat. It can recover deleted mails and convert them into PST file. It has PST splitting users can split PST file into multiple small sizes. It support all version of Windows OS.