This is an error you run into when the JVM Heap tells you “Enough is enough. I can’t fit all of this into my memory.” Which usually means that the application has become unstable and should be restarted before it crashes and that you also have a real problem to solve.
The following things can cause this error:
You can refer to this doc.
you can correct this by
Settings→ config.→ Size
Hope it helps!
There are too many objects in memory. This can be, for example, due to a memory leak. Or just a big application and too little memory.
You can up the standard java heap size in the settings.
After that, check the JVM analyses tool from the JDK. Which after connecting to your running Mendix app, gives you insight in the usage: