Adobe Acrobat prompts''Sign In Required''

From Adobe support:
After you get the serial number you can disable the sign in prompt using the below workflow.

1. Download the Acrobat Customization Wizard (CW) from: Adobe Customization Wizard
2. Launch the CW and open the package for Acrobat (Acropro.msi)
3. Provide the serial number in the 'Personalization Options' tab and click on Grant Offline Exception button.
4. Save the package and use the Setup.exe to install the customized build.
Make sure that the machine on which CW is installed is connected to internet.

FYI You can't skip registration part if you don't have a volume serial key. Users are required to register.

Otherwise I suggest to ask your question here: https://forums.adobe.com/welcome

You must sign in to use Adobe Acrobat DC after installation and complete the sign in (or else it will return).

If you have successfully signed in and you still cannot run Adobe without signing in, try Adobe support as suggested above.

There were some old entries on host file related to Adobe. I just removed and reinstalled adobe acrobat. Successfully installed.