When you enable Shared Configuration in IIS Manager, you may enter a UNC path and credentials, click Apply, and see this error:
Cannot connect to the specified path. Make sure that the path and credentials are valid.
The message doesn’t say which part failed. Check the path, the account IIS uses to access it, and the permissions on the share.
Verify the UNC path
Use the actual network share path, such as \\FileServer\IISConfig$. Confirm the share name and folder on the file server. A local path or mapped drive is not a substitute for the UNC path IIS needs to access.
Check the account and permissions
The credentials entered for Connect As must be valid for accessing the file server. Confirm that the account has the permissions required for the configuration share, considering both share and file-system permissions.
In a workgroup or non-domain environment, Microsoft’s IIS guidance calls for a matching local account on both the web server and the file server, using the same username and password. A local account created on only one machine may not work for this setup.
In a domain environment, use an appropriate domain account and grant it the required access to the share.
Keep the two passwords separate
The Connect As credentials provide access to the UNC share. IIS may also ask for the password used to protect the exported configuration encryption keys. That is a separate password; entering the share credentials in that prompt will not unlock the keys.
Test from the web server
Before retrying the configuration, verify that the web server can reach the UNC path using the same account configured in Connect As. A path that opens for your signed-in administrator account does not prove that the configured account has access.
Once the path, account, permissions, and encryption-key password are confirmed, apply Shared Configuration again.
Further reading: Shared Configuration with IIS