how do i remove adware from safari?

Clickhereand follow the instructions, or if you'd rather not remove the adware manually, runMalwareBytes for Mac.

MalwareBytes simplifies the process of removing adware but doesn't stop it or other malware from getting onto the computer. It shouldn’t be relied on to prevent future incidents; instead, avoid downloading software from sources other than the Mac App Store or the developer websites.

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Try going to Safari/Preferences/Extensions and disable all extensions. Quit Safari, reopen, and see if the website will now load. If so, enable extensions one or two at a time until you find which extension is causing the problem.