"Cannot open Google Chrome or Firefox on MacBook Air: Hi everyone, purchased a new macboook air but I face some issues when I am trying to download and use browser other than Safari. I had tried with Google Chrome and Firefox but I am unable to open both the browser and this pop out (may refer to the image)."
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Profile being the Culprit:
Who is the seller? You may have purchased a used one that was not configured properly. Is this a school- or company-owned device? If so, talk with he administrator, asking them to permit this in a profile. Profiles are configured with Apple Configurator. If purchased used, then have this reset, once more, is the site the seller should have used prior to selling it to you: What to do Before you Sell, Give Away, Trade in, or Recycle your Mac - Apple Support