VERIFIED SOLUTION i
When user tries to save newly created customer domain, saving continues forever and after 10 minutes com+ time exceeded error comes up.
When PD is freshly installed then instance folder is created inside PST folder and customer domain folder gets created inside instances folder and PD saves this path in dialog admin->General admin->System global->RootPathUNC.
ResolutionUPDATED: August 24, 2017
And if user tries to reinstall and wants to use different path for customer domain then this path needs to be changed in dialog admin if this is not changed then PD installer will pick the last path and user will not be able to save customer domain.