How do I resolve the error “java.lang​.Unsatisfi​edLinkErro​r: nativemvm.dll already loaded in another classloader” when running a Java Engine program?

I have a Java source code that calls MATLAB via MATLAB Engine API. I compiled a .WAR file from the Java source code on Windows 7. Then I deployed the .WAR file to Windows Server 2016 using JBoss EAP, and got the following error: 

ERROR: java.lang.UnsatisfiedLinkError: Native Library C:\Program Files\MATLAB\R2019a\bin\win64\nativemvm.dll already loaded in another classloader

I have MATLAB R2019a installed on both Windows 7 and Windows Sever 2016. Before deploying the .WAR file, I added "C:\Program Files\MATLAB\R2019a\bin\win64" to the PATH variable on Windows Server 2016 and added “C:\Program Files\MATLAB\R2019a\extern\engines\java\jar\engine.jar” to the “classpath” in JBoss. 

How do I resolve this "nativemvm.dll" error?

Answer 1

[MathWorks Support Team]

Apart from setting the PATH variable and the "classpath", you also need to make sure that your Java environment is configured properly on Windows Server. Specifically, you need to make sure that the environment variable "JAVA_HOME" is set to be the path of your JDK installation, which is the directory that contains the "bin" folder.