Hope you are doing great.
This issue occurs when the firewall is enabled, and Designer is not one of the selected applications in the exceptions list within the *Exceptions*tab.
When you enable the Windows Firewall, from *Control Panel > Windows Firewall> Exceptions *tab ensure that all PowerCenter clients are checked in the list of exceptions so that incoming communications to these clients are not blocked.
Also please verify the below details:
Can you please check the services.msc in your local machine that the Informatica Services are running fine.
This is a common issue with Windows OS as Informatica is completely a server software and we are forcefully doing it in windows so it may give you this error.
To solve the issue we have to check that services should be running so we will not face this issue.
Below are the screenshot for your reference:
Please try at your end and let us know if you face any issue so we can help you out.