The issue with MirHosting SSL certificate is known. We hope, it is going to be fixed soon.
The certificate is not included to Java cacerts by default. So Java applications (including Studio) could not work with MirHosting API.
There are two ways to work around the issue:
The easiest is to build WAR using Studio and deploy the application using Jelastic administration panel.
When Jelastic deployment is configured launch the jelasticBuildWar Gradle task. As a result, “Jelastic ready” WAR will be generated in the ${project_root}/build/distributions/war folder.
The second way is a bit complicated but enables Studio to work with MirHosting. The certificate could be added to trusted certs of your local Java installation. How to do it: