Acrobat 2021 can't sign in. Update. required . Why?

[Liu5CBD]

There are 4 computers in my office, including 1 ordinary PC, 1 laptops and 2 MacBookpros, all of which are installed with the latest version of win 10 64 bit. With Acrobat 2021 installed, the other 3 Pcs can sign in, but only one MACBookPro can't. The software installed on several computers is not exactly the same. I want to know why this one doesn't work, how to test which software conflicts, and what the Photoshop calls to sign in?

I had tried to import reg (https://helpx.adobe.com/content/dam/help/en/x-productkb/global/update-operating-system-and-browser/j...but can not sign in too.

Thank you

[Liu5CBD]

I had installed Photoshop 2021 and uninstalled IE later, but I still couldn't sign in. Please give me a guidance ervery expert . Thank you

[Liu5CBD]

By process monitor , this problem is solved . Only delete HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\CurrentVersion\Internet Settings\useragent or Proxysettingsperuser  's  value just like MSIE 9.0  . OMG It took me almost a week.