Hello, I am new to ktor. I have built a restful AP...

# ktor

[Joe Altidore]

Hello, I am new to ktor. I have built a restful API service with ktor and is working well when run locally but after deploying to Heroku, I get the error below and I am lost on how to resolve the issue.

Error: A JNI error has occurred, please check your installation and try again
2022-08-01T00:00:03.922254+00:00 app[web.1]: Exception in thread "main" java.lang.UnsupportedClassVersionError: com/impact/ApplicationKt has been compiled by a more recent version of the Java Runtime (class file version 55.0), this version of the Java Runtime only recognizes class file versions up to 52.0
2022-08-01T00:00:03.922349+00:00 app[web.1]: at java.lang.ClassLoader.defineClass1(Native Method)
2022-08-01T00:00:03.922384+00:00 app[web.1]: at java.lang.ClassLoader.defineClass(ClassLoader.java:756)
2022-08-01T00:00:03.922539+00:00 app[web.1]: at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
2022-08-01T00:00:03.922575+00:00 app[web.1]: at <http://java.net|java.net>.URLClassLoader.defineClass(URLClassLoader.java:473)
2022-08-01T00:00:03.922623+00:00 app[web.1]: at <http://java.net|java.net>.URLClassLoader.access$100(URLClassLoader.java:74)
2022-08-01T00:00:03.922664+00:00 app[web.1]: at <http://java.net|java.net>.URLClassLoader$1.run(URLClassLoader.java:369)
2022-08-01T00:00:03.922700+00:00 app[web.1]: at <http://java.net|java.net>.URLClassLoader$1.run(URLClassLoader.java:363)
2022-08-01T00:00:03.922740+00:00 app[web.1]: at java.security.AccessController.doPrivileged(Native Method)
2022-08-01T00:00:03.922774+00:00 app[web.1]: at <http://java.net|java.net>.URLClassLoader.findClass(URLClassLoader.java:362)
2022-08-01T00:00:03.922808+00:00 app[web.1]: at java.lang.ClassLoader.loadClass(ClassLoader.java:418)
2022-08-01T00:00:03.922842+00:00 app[web.1]: at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:352)
2022-08-01T00:00:03.922883+00:00 app[web.1]: at java.lang.ClassLoader.loadClass(ClassLoader.java:351)
2022-08-01T00:00:03.922922+00:00 app[web.1]: at sun.launcher.LauncherHelper.checkAndLoadMain(LauncherHelper.java:601)

[Aleksei Tirman [JB]]

Please try to configure Heroku to use JAVA 11 https://devcenter.heroku.com/changelog-items/1489

[Joe Altidore]

@Aleksei Tirman [JB] Thanks a lot. This solved my problem.