That's usually caused by one of two things:
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Antivirus getting in the way of the installer.
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The Windows account is messed up and breaking some installers. A few people have seen this in the last year or so, with the Opus installer and some others. We don't know the cause, but a solution is to temporarily create and use a fresh Windows account to run the installer, after which it will work again.
Those are explained in more detail in this guide: