Easily With the Simplest Solutions Fix Error Code 1603 for Office 2021 or Office 2019 Or Microsoft 365. When you put in Office on windows 11 or windows 10, you could see error code 1603 if an advanced setup of Office 365/2021/2019 failed. Here are a few methods that you could try and repair office setup error code 1603. But earlier than intended beforehand first appearance the maximum not unusual place reasons of this office 365/2021/2019 error code 1603 below.