Learn how to fix “Microsoft Defender SmartScreen has blocked this unsafe content” error on your WordPress site by following the instructions in this post.
Recently a website visitor emailed me because his Edge browser flagged one of my WordPress website pages as unsafe content.
The page that was marked as unsafe was Astra Training Videos.
I really appreciated him reaching out to alert me of the problem.
And the first thing I had to make sure of was that my WordPress site wasn’t hacked!
The good news is that it wasn’t.
But the bad news was that I could not recreate the issue my visitor had experienced with Edge on my Windows 10 machine.
The Error: Microsoft Defender SmartScreen Blocks Unsafe Content
So the visitor was kind enough to send along the screen he was seeing:
Now once I was confident that my site was safe, I knew it was possible to mark it as safe. And you can read more about that here.
Though I was tempted to do that I felt like it would be putting a band-aid on a bigger problem that would just keep resurfacing.
I wanted to get to the root problem to see exactly why a visitor using Edge encountered this issue.
And I didn’t want to have to deal with this issue in the future.
So I set out to find the reason for the error.
And then I needed to fix “Microsoft Defender SmartScreen has blocked this unsafe content” error.
The Reason: Lazy Loading of Embedded YouTube Videos
I narrowed the issue down to pages with lazy loading of embedded YouTube video that were being viewed with Microsoft Edge browser.
But Firefox and Chrome worked just fine.
After further in-depth analysis, it appeared to be an issue with the Lazy Load Settings of WP-Fastest-Cache Premium plugin that triggered the error in the Edge browser.
See highlighted area below:
I reached out to the developer of WP-Fastest-Cache plugin and he replied that this error was related to the lazy load feature.
The Fix: Microsoft Defender SmartScreen Blocks Unsafe Content
So here is how to fix Microsoft Defender SmartScreen has blocked this unsafe content error.
1. Log into your WordPress dashboard and go to WP Fastest Cache > Settings.
2. Check the Lazy Load setting:
3. The following screen appears:
Choose the Image Placeholder. By default a blank image is used.
4. Click Next
5. The following screen appears:
Type “iframe” in the “Add Keyword” box and hit enter.
NOTE: Press enter or the keyword will not save.
If the word “iframe” is in an orange box, you’ve successfully saved it:
6. Click Finish.
YouTube iframe embeds will now be excluded from Lazy Load.
At this point, your page should no longer throw the “Microsoft Defender SmartScreen has blocked this unsafe content” error.
I hope this tutorial was useful to you.
Please post any questions in the comments below.