2591258 - ERROR in Selftest. Return code: 3 during start of SWPM Tool (sapinst)

When starting Software Provisioning Manager (SWPM) following error appears:

ERROR in Selftest. Return code: 3

You can find more details about the root cause in sapinst_dev.log inside installation user's .sapinst folder (UNIX: /<$HOME of root>/.sapinst/<hostname>, Windows: <x>:\Users\<user>\.sapinst) similar to:

Case 1:

Selftest output:
Connecting to: https://<host.domain>:4237
executing: GET /sapinst/slp/whoami HTTP/1.1
org.apache.http.conn.HttpHostConnectException: Connect to <host.domain>:4237 [<host.domain>/<IP>]
failed: Connection refused (Connection refused) (local port <portnr> to address <IP> (<host.domain>), remote port 4237 to address <IP> (<host.domain>))
Exit code: 3

or 

Selftest output:
Connecting to: https://<host.domain>:4237
executing: GET /sapinst/slp/whoami HTTP/1.1
javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
Exit code: 3

Case 2:

Selftest output:
Connecting to: https://<virtualhost.domain>:4237
executing: GET /sapinst/slp/whoami HTTP/1.1
org.apache.http.conn.HttpHostConnectException: Connect to <virtualhost.domain>:4237 [<virtualhost.domain>/<virtualIP>] failed: Connection refused (Connection refused) (local port <portnr> to address <virtualIP> (<virtualhost.domain>), remote port <portnr> to address <virtualIP> (<virtualhost.domain>))
Exit code: 3

Case 3:

Selftest output:
Connecting to: https://<virtualhost.domain>:4237
executing: GET /sapinst/slp/whoami HTTP/1.1
javax.net.ssl.SSLPeerUnverifiedException: Certificate for <virtualhost.domain> doesn't match any of the subject alternative names: []
Exit code: 3

Read more...

• SAP System installation using SWPM
• All SAP System based on SAP NetWeaver 7.0 and higher (7.0X, 7.X)

SAP NetWeaver 7.0 ; SAP NetWeaver 7.1 ; SAP NetWeaver 7.2 ; SAP NetWeaver 7.3 ; SAP NetWeaver 7.4 ; SAP NetWeaver 7.5 ; SAP enhancement package 1 for SAP NetWeaver 7.0 ; SAP enhancement package 1 for SAP NetWeaver 7.3 ; SAP enhancement package 2 for SAP NetWeaver 7.0 ; SAP enhancement package 3 for SAP NetWeaver 7.0

"=>sapparam(1c): No Profile used." "=>sapparam: SAPSYSTEMNAME neither in Profile nor in Commandline" doesn't match any of the subject alternative names "doesn't match any of the subject alternative names" failed: Connection refused Exit code: 3

, KBA , BC-INS-SUI , UI component for SWPM , BC-INS-SWPM , Installation with Software Provisioning Manager , BC-INS-FWK , sapinst, slcb, elmbridge, elm replication service , Problem