Defender SmartScreen for Windows 11 can trigger video playback issues

by Alexandru Poloboc
Alexandru Poloboc
Alexandru Poloboc
News Editor
With an overpowering desire to always get to the bottom of things and uncover the truth, Alex spent most of his time working as a news reporter, anchor,... read more
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  • Windows Defender is an antivirus used by a large number of people, even though not the most popular.
  • Recent security rankings tests have included Defender and the software scored pretty big on the charts.
  • However, Microsoft's antivirus software isn't free of bugs or errors and users are reporting new issues.
  • This time around, Defender seems to be the root cause of some pretty nasty video playback problems.

What can be said about Microsoft’s antivirus solution? Well, even though it’s not as popular as other similar software out there, it is still ranked pretty high, efficiency-wise.

There still are a lot of people that rely on Defender for protection and it seems to be pretty stable. At least, it seemed to, until Microsoft released the latest Windows 11 Beta build.

Things going haywire isn’t something new on the tech giant’s plate, but having issues with the one software that is supposed to keep you safe isn’t something to take lightly.

Many users that have been actively testing build 22581 are reporting severe video playback delays that are caused by the antivirus.

MKV files seem to be the victims, but other video container formats may also be affected, as ISOs are apparently also facing this delayed execution problem.

This caught many off-guard, as this issue isn’t listed among the known problems for the build which means it probably went undetected during testing.

However, not all is lost, as with every problem, there is bound to be a solution, even if we are talking about a temporary one, for the time being.

A simple workaround for this issue is disabling the Check apps and files option under SmartScreen settings.

Users trying this were able to resolve the issue. But before proceeding to apply this workaround, make sure the file type is actually trustworthy.

Have you also encountered this issue with Defender on Windows 11’s latest Beta build 22581? Let us know in the comments section below.

Still having issues? Fix them with this tool:


If the advices above haven't solved your issue, your PC may experience deeper Windows problems. We recommend downloading this PC Repair tool (rated Great on to easily address them. After installation, simply click the Start Scan button and then press on Repair All.

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