When installing unity, to the time of installation vs being given this application requires .net Framework 4.6 or higher to be installed
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Solution:
Only to https://go.microsoft.com/fwlink/?linkid=840938 download and install the new version of the .Net Framework;
Or link: https://download.csdn.net/download/qq_33404596/11169500
Download: https://www.microsoft.com/zh-CN/download/details.aspx?id=48137