Here are details of the launcher:

Thanks for your reply. That's exactly what I did. Yesterday I purchased Spine Essential, received an email with the Spine Essential licence, clicked on the license page link contained within and then downloaded Spine from the Frankfurt server. Was able to launch successfully the first time, then 2nd time received the ;Sorry the server cannot be contacted; message. Then uninstalled / reinstalled from the same page multiple times. Restarted computer.

I have done the exact same steps today and now it works. Which I am very happy about. But not sure why it works today and not yesterday....

I have just purchased Spine Essentials, downloaded the dmg from my nearest server (Germany). I installed Spine successfully, was able to launch it and, on seeing that the resolution was tiny, went to Settings and set the interface resolution to the maximum setting. I then quit Spine and relaunched and then got the 'Sorry, the server could not be contacted' message.

I've uninstalled and reinstalled Spine. I don't have a firewall running.

I launched Spine from the command line and get the following error message. Can you help? :

Spine Launcher 3.7.41
Esoteric Software LLC (C) 2013-2018
Warning: the fonts "Times" and "Lucida Bright" are not available for the Java logical font "Serif", which may have unexpected appearance or behavior. Re-enable the "Times" font to remove this warning.
Mac OS X x86_64 10.16
Unable to reach server (EU):
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
   at java.base/sun.security.ssl.Alerts.getSSLException(Unknown Source)
   at java.base/sun.security.ssl.SSLSocketImpl.fatal(Unknown Source)
   at java.base/sun.security.ssl.Handshaker.fatalSE(Unknown Source)
   at java.base/sun.security.ssl.Handshaker.fatalSE(Unknown Source)
   at java.base/sun.security.ssl.ClientHandshaker.checkServerCerts(Unknown Source)
   at java.base/sun.security.ssl.ClientHandshaker.serverCertificate(Unknown Source)
   at java.base/sun.security.ssl.ClientHandshaker.processMessage(Unknown Source)
   at java.base/sun.security.ssl.Handshaker.processLoop(Unknown Source)
   at java.base/sun.security.ssl.Handshaker.processRecord(Unknown Source)
   at java.base/sun.security.ssl.SSLSocketImpl.processInputRecord(Unknown Source)
   at java.base/sun.security.ssl.SSLSocketImpl.readRecord(Unknown Source)
   at java.base/sun.security.ssl.SSLSocketImpl.readRecord(Unknown Source)
   at java.base/sun.security.ssl.SSLSocketImpl.performInitialHandshake(Unknown Source)
   at java.base/sun.security.ssl.SSLSocketImpl.startHandshake(Unknown Source)
   at java.base/sun.security.ssl.SSLSocketImpl.startHandshake(Unknown Source)
   at java.base/sun.net.www.protocol.https.HttpsClient.afterConnect(Unknown Source)
   at java.base/sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.connect(Unknown Source)
   at java.base/sun.net.www.protocol.https.HttpsURLConnectionImpl.connect(Unknown Source)
   at tzax.w.run(SourceFile:1183)
Caused by: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
   at java.base/sun.security.validator.PKIXValidator.doBuild(Unknown Source)
   at java.base/sun.security.validator.PKIXValidator.engineValidate(Unknown Source)
   at java.base/sun.security.validator.Validator.validate(Unknown Source)
   at java.base/sun.security.ssl.X509TrustManagerImpl.validate(Unknown Source)
   at java.base/sun.security.ssl.X509TrustManagerImpl.checkTrusted(Unknown Source)
   at java.base/sun.security.ssl.X509TrustManagerImpl.checkServerTrusted(Unknown Source)
   ... 15 more
Caused by: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
   at java.base/sun.security.provider.certpath.SunCertPathBuilder.build(Unknown Source)
   at java.base/sun.security.provider.certpath.SunCertPathBuilder.engineBuild(Unknown Source)
   at java.base/java.security.cert.CertPathBuilder.build(Unknown Source)
   ... 21 more
Unable to reach server:
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
   at java.base/sun.security.ssl.Alerts.getSSLException(Unknown Source)
   at java.base/sun.security.ssl.SSLSocketImpl.fatal(Unknown Source)
   at java.base/sun.security.ssl.Handshaker.fatalSE(Unknown Source)
   at java.base/sun.security.ssl.Handshaker.fatalSE(Unknown Source)
   at java.base/sun.security.ssl.ClientHandshaker.checkServerCerts(Unknown Source)
   at java.base/sun.security.ssl.ClientHandshaker.serverCertificate(Unknown Source)
   at java.base/sun.security.ssl.ClientHandshaker.processMessage(Unknown Source)
   at java.base/sun.security.ssl.Handshaker.processLoop(Unknown Source)
   at java.base/sun.security.ssl.Handshaker.processRecord(Unknown Source)
   at java.base/sun.security.ssl.SSLSocketImpl.processInputRecord(Unknown Source)
   at java.base/sun.security.ssl.SSLSocketImpl.readRecord(Unknown Source)
   at java.base/sun.security.ssl.SSLSocketImpl.readRecord(Unknown Source)
   at java.base/sun.security.ssl.SSLSocketImpl.performInitialHandshake(Unknown Source)
   at java.base/sun.security.ssl.SSLSocketImpl.startHandshake(Unknown Source)
   at java.base/sun.security.ssl.SSLSocketImpl.startHandshake(Unknown Source)
   at java.base/sun.net.www.protocol.https.HttpsClient.afterConnect(Unknown Source)
   at java.base/sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.connect(Unknown Source)
   at java.base/sun.net.www.protocol.https.HttpsURLConnectionImpl.connect(Unknown Source)
   at tzax.w.run(SourceFile:1183)
Caused by: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
   at java.base/sun.security.validator.PKIXValidator.doBuild(Unknown Source)
   at java.base/sun.security.validator.PKIXValidator.engineValidate(Unknown Source)
   at java.base/sun.security.validator.Validator.validate(Unknown Source)
   at java.base/sun.security.ssl.X509TrustManagerImpl.validate(Unknown Source)
   at java.base/sun.security.ssl.X509TrustManagerImpl.checkTrusted(Unknown Source)
   at java.base/sun.security.ssl.X509TrustManagerImpl.checkServerTrusted(Unknown Source)
   ... 15 more
Caused by: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
   at java.base/sun.security.provider.certpath.SunCertPathBuilder.build(Unknown Source)
   at java.base/sun.security.provider.certpath.SunCertPathBuilder.engineBuild(Unknown Source)
   at java.base/java.security.cert.CertPathBuilder.build(Unknown Source)
   ... 21 more
Unable to reach server (EU):
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
   at java.base/sun.security.ssl.Alerts.getSSLException(Unknown Source)
   at java.base/sun.security.ssl.SSLSocketImpl.fatal(Unknown Source)
   at java.base/sun.security.ssl.Handshaker.fatalSE(Unknown Source)
   at java.base/sun.security.ssl.Handshaker.fatalSE(Unknown Source)
   at java.base/sun.security.ssl.ClientHandshaker.checkServerCerts(Unknown Source)
   at java.base/sun.security.ssl.ClientHandshaker.serverCertificate(Unknown Source)
   at java.base/sun.security.ssl.ClientHandshaker.processMessage(Unknown Source)
   at java.base/sun.security.ssl.Handshaker.processLoop(Unknown Source)
   at java.base/sun.security.ssl.Handshaker.processRecord(Unknown Source)
   at java.base/sun.security.ssl.SSLSocketImpl.processInputRecord(Unknown Source)
   at java.base/sun.security.ssl.SSLSocketImpl.readRecord(Unknown Source)
   at java.base/sun.security.ssl.SSLSocketImpl.readRecord(Unknown Source)
   at java.base/sun.security.ssl.SSLSocketImpl.performInitialHandshake(Unknown Source)
   at java.base/sun.security.ssl.SSLSocketImpl.startHandshake(Unknown Source)
   at java.base/sun.security.ssl.SSLSocketImpl.startHandshake(Unknown Source)
   at java.base/sun.net.www.protocol.https.HttpsClient.afterConnect(Unknown Source)
   at java.base/sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.connect(Unknown Source)
   at java.base/sun.net.www.protocol.https.HttpsURLConnectionImpl.connect(Unknown Source)
   at tzax.w.run(SourceFile:1183)
Caused by: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
   at java.base/sun.security.validator.PKIXValidator.doBuild(Unknown Source)
   at java.base/sun.security.validator.PKIXValidator.engineValidate(Unknown Source)
   at java.base/sun.security.validator.Validator.validate(Unknown Source)
   at java.base/sun.security.ssl.X509TrustManagerImpl.validate(Unknown Source)
   at java.base/sun.security.ssl.X509TrustManagerImpl.checkTrusted(Unknown Source)
   at java.base/sun.security.ssl.X509TrustManagerImpl.checkServerTrusted(Unknown Source)
   ... 15 more
Caused by: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
   at java.base/sun.security.provider.certpath.SunCertPathBuilder.build(Unknown Source)
   at java.base/sun.security.provider.certpath.SunCertPathBuilder.engineBuild(Unknown Source)
   at java.base/java.security.cert.CertPathBuilder.build(Unknown Source)
   ... 21 more
Unable to reach server:
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
   at java.base/sun.security.ssl.Alerts.getSSLException(Unknown Source)
   at java.base/sun.security.ssl.SSLSocketImpl.fatal(Unknown Source)
   at java.base/sun.security.ssl.Handshaker.fatalSE(Unknown Source)
   at java.base/sun.security.ssl.Handshaker.fatalSE(Unknown Source)
   at java.base/sun.security.ssl.ClientHandshaker.checkServerCerts(Unknown Source)
   at java.base/sun.security.ssl.ClientHandshaker.serverCertificate(Unknown Source)
   at java.base/sun.security.ssl.ClientHandshaker.processMessage(Unknown Source)
   at java.base/sun.security.ssl.Handshaker.processLoop(Unknown Source)
   at java.base/sun.security.ssl.Handshaker.processRecord(Unknown Source)
   at java.base/sun.security.ssl.SSLSocketImpl.processInputRecord(Unknown Source)
   at java.base/sun.security.ssl.SSLSocketImpl.readRecord(Unknown Source)
   at java.base/sun.security.ssl.SSLSocketImpl.readRecord(Unknown Source)
   at java.base/sun.security.ssl.SSLSocketImpl.performInitialHandshake(Unknown Source)
   at java.base/sun.security.ssl.SSLSocketImpl.startHandshake(Unknown Source)
   at java.base/sun.security.ssl.SSLSocketImpl.startHandshake(Unknown Source)
   at java.base/sun.net.www.protocol.https.HttpsClient.afterConnect(Unknown Source)
   at java.base/sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.connect(Unknown Source)
   at java.base/sun.net.www.protocol.https.HttpsURLConnectionImpl.connect(Unknown Source)
   at tzax.w.run(SourceFile:1183)
Caused by: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
   at java.base/sun.security.validator.PKIXValidator.doBuild(Unknown Source)
   at java.base/sun.security.validator.PKIXValidator.engineValidate(Unknown Source)
   at java.base/sun.security.validator.Validator.validate(Unknown Source)
   at java.base/sun.security.ssl.X509TrustManagerImpl.validate(Unknown Source)
   at java.base/sun.security.ssl.X509TrustManagerImpl.checkTrusted(Unknown Source)
   at java.base/sun.security.ssl.X509TrustManagerImpl.checkServerTrusted(Unknown Source)
   ... 15 more
Caused by: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
   at java.base/sun.security.provider.certpath.SunCertPathBuilder.build(Unknown Source)
   at java.base/sun.security.provider.certpath.SunCertPathBuilder.engineBuild(Unknown Source)
   at java.base/java.security.cert.CertPathBuilder.build(Unknown Source)
   ... 21 more