Outlook 2016 preview uninstalled
There may be issues, if you go back to Outlook 2013, after testing Outlook 2016 preview. To fix this issue, please follow the steps below:
1. Open your System Control Panel, go to "Programs and Features", search for Microsoft Office 2013 and select "Change"
2. Select "Repair" and continue. When it's finished, reboot your system. Now yasoon should be working again.