When connecting to Linchpin Mobile Gateway the 'Internal request' connection test fails due to an error.
If this check fails the system is not able to perform http requests to its own address. In most cases this is caused by the network configuration.
In many cases Confluence uses a gateway to perform http requests. This gateway was not able to access the Confluence server and returned a 404 http status code.
The network configuration must be adjusted so that Confluence can reach itself via http requests.
For self-signed or custom CA certificates that allow HTTPS access to your Confluence system, this connection test may fail with the following error message:
SSLHandshakeException: PKIX path building failed:
sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
In this case, please check that the TrustStore of your Confluence JVM contains the certificate(s) needed to access Confluence. Connecting to SSL services in the Atlassian Knowledge Base has more details on how to set this up. The JVM usually needs to be restarted so it can pick up the configuration changes.