How do I save my add-in to Office 365?

Question

How do I save my add-in to Office 365?

When we add our add-in to Excel online, it sometimes appears as a white rectangle. After further investigation, we found that the add-in was handled correctly, but many elements were created above it div

.

We were able to reproduce the issue by scrolling the browser window up and down quickly, as shown in the following gif file:

Keep in mind that it loads multiple times with a div at the top, scrolling up and down just reproduces the problem.

We created a minimal add-on and tested it again and got the same results:

<!DOCTYPE html>
<html style="height: 100%">

<head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=Edge" />
    <title>Test Init</title>
    <script src="//appsforoffice.microsoft.com/lib/1/hosted/office.js"></script>
</head>

<body class="ms-font-l" style="width:100%;height:100%;overflow:hidden;position:relative;">
<div id="app" style="height:100%"></div>
<script>
    console.log('Our script loaded...');
    Office.initialize = function () {
        console.log('Our App Initialized!!!')
    };
</script>
</body>

</html>