We get this kind of exceptions in gui-application when using AdoptOpenJDK v. 11 and Jar2exe 2.5:

210118:064115.617 Session started
java.lang.reflect.InvocationTargetException
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:566)
at org.springframework.boot.loader.MainMethodRunner.run(MainMethodRunner.java:48)
at org.springframework.boot.loader.Launcher.launch(Launcher.java:87)
at org.springframework.boot.loader.Launcher.launch(Launcher.java:50)
at com.regexlab.j2e.Jar2ExeLauncher.main(Jar2ExeLauncher.java:48)
Caused by: java.lang.NoClassDefFoundError: org/jasypt/exceptions/EncryptionOperationNotPossibleException
at com.cardiscope.db.MainInstance.<init>(MainInstance.java:70)
at com.cardiscope.db.DatabaseConfig.scanConfigurations(DatabaseConfig.java:169)
at com.cardiscope.db.DatabaseConfig.<init>(DatabaseConfig.java:136)
at com.cardiscope.db.DatabaseConfig.main(DatabaseConfig.java:564)
... 8 more
Caused by: java.lang.ClassNotFoundException: org.jasypt.exceptions.EncryptionOperationNotPossibleException
at java.base/java.net.URLClassLoader.findClass(URLClassLoader.java:471)
at com.regexlab.j2e.Jar2ExeClassLoader.findClass(Jar2ExeClassLoader.java:107)
at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:589)
at org.springframework.boot.loader.LaunchedURLClassLoader.loadClass(LaunchedURLClassLoader.java:93)
at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:522)
... 12 more

The exe has been converted with options:

/type windows /minjre 11 /platform windows /amd64 /encrypt /checksum:false /runasadmin /config "libs ./lib" /config "jre_order cesi" /authorize