Error: "The file you are attempting to preview could harm your computer."

Problem

After updating Windows, you receive the following error when trying to preview a PDF in Windows Explorer:

The file you are attempting to preview could harm your computer. If you trust the file and the source you received it from, open it to view its contents.

Cause

This error occurs after either of the following Windows updates are installed on your computer:

• Windows 10 KB5066791

• Windows 11 25H2

For more information, see this Microsoft article.

Solution

This issue lies with the specified Windows updates and not with Revu. We suggest you reach out to your IT department to discuss Windows update options.

Troubleshooting

Revu 21

Revu 20

Error Message

Revu