Update Excel 2010 To 2016. If this does not work retry the steps but choose online repair instead. July 12 2016 kb3115322.
This update has a prerequisite. Choose your version of office. After you install this new update excel 2010 will open html documents even if they re renamed as xls files in.
This issue occurs after you install ms16 088.
If no updates are available you won t see an update progress window appear. Select quick repair repair. If no updates are available you won t see an update progress window appear. If this does not work retry the steps but choose online repair instead.