class - fully qualified name of a class which extends Runnable.
This is not complete information.
According to source code, menu item class can also implement Consumer<Map<String, Object>> or com.haulmont.cuba.gui.config.MenuItemRunnable.
throw new IllegalStateException(
String.format("Class \"%s\" must implement Runnable or Consumer<Map<String, Object>> or MenuItemRunnable",
runnableClass));
Environment
Description of the bug or enhancement
This is not complete information.
According to source code, menu item class can also implement
Consumer<Map<String, Object>>
orcom.haulmont.cuba.gui.config.MenuItemRunnable
.