” The remote computer refused the network connection" how to solve this issue??

[Divya G_]

I validate the credentials it sucessfully validating and port is also open

[Anshu_Anand_]

Have you checked from mid server if its replying to the request from target server.

Its seems when you try to discover the device via mid server, the remote device refused to response the mid server request.

You have to change in firewall settings of the remote device to allow mid server Host to interact bi-directionally.

There could be multiple reasons, as mentioned in this KB

https://support.servicenow.com/kb?id=kb_article_view&sysparm_article=KB0564283

Mark answer as correct if its helpful

[Divya G_]

How to check "Have you checked from mid server if its replying to the request from target server."

[Anshu_Anand_]

We can try to run a simple Powershell WMI query directly from the MID Server to the remote machine. 
Open a PowerShell command line and run the following:

gwmi win32_operatingsystem -computer 192.168.200.14 -credential 'LOCALDOMAIN\mid'

Substitute LOCALDOMAIN\mid by the credential that you want to test. The expected is something similar to:

SystemDirectory : C:\Windows\system32
Organization    :
BuildNumber     : 6001
RegisteredUser  : Windows User
SerialNumber    : 12345-OEM-1234567-12345
Version         : 6.0.6001

https://support.servicenow.com/kb?id=kb_article_view&sysparm_article=KB0549834

[Richard Hine]

It depends on what the remote computer is to be honest.

If it is a windows device then the credential validation will only be checking port 135 and other ports are in play that may not be open.

Assuming you have placed your MID as close to the remote computer as possible without firewalls in between then you may be looking at a firewall or port blocking on the remote computer itself.

A bit more detail on what the remote computer is would help.

Thanks,

Richard