Remove office related credential in Credential Manager > Generic Credential and sign in back http://answers.microsoft.com/en-us/msoffice/forum/msoffice_account/onedrive-business-login-prompt-when-i-save-as-in/98f9d8bd-aa7c-4eac-a89f-4afdecdcba14
Error message 1 An unknown error has occurred. 0x80040119Error message 2 An unknown error has occurred. 0x80040600Or, when you try to delete email messages, you may receive the following error message: Messaging interface has caused an unknown error ...