Constant console errors in SharePoint Online

I just finished building my first SharePoint Online page. Just a simple page with a few standard web parts (image, news, document library, list, events, file embed). Everything seems to work okay (except for what appears to be a margin-right CSS issue on the news web part) but I’m getting a nonstop trickle of console errors coming in the longer I stay on the page.

For example, I’m in Chrome and did a fresh reload of the page when starting to type up this question, and in 2-3 minutes I’m up to 85 errors and 12 warnings. The errors are all over the place from

Warning! Use of this tool exposes you to potential security threats which can result in others gaining access to your personal Office 365 data (documents, emails, conversations and more). Make sure you trust the person or organization that asked you to access this tool before proceeding.

warning security threat

to mixed content errors related to a

Mixed Content: The page at ” was loaded over HTTPS, but requested an insecure XMLHttpRequest endpoint ”. This request has been blocked; the content must be served over HTTPS.

to errors that seem to be related to the PowerPoint embed I have:

Access to XMLHttpRequest at ‘’ from origin ‘’ has been blocked by CORS policy: No ‘Access-Control-Allow-Origin’ header is present on the requested resource.

Given my level of experience with SharePoint (literally nonexistent), I wouldn’t be totally surprised if I’m doing something wrong but given that I haven’t used any custom web parts or done any other theming, I’m a little perplexed as to what it could be.

Is it normal to get all these console errors?