Any External Authoring Interface (EAI) capable VRML browser (including browsers with plugins such as Blaxxun Contact and Cortona) should work with VRSpace. However, only the Blaxxun plugin has been thoroughly tested.
java.lang.NoClassDefFoundError: vrml/external/field/EventOutObserver
at java.lang.ClassLoader.defineClass0(Native Method)
at java.lang.ClassLoader.defineClass(Unknown Source)
at java.security.SecureClassLoader.defineClass(Unknown Source)
at sun.applet.AppletClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
...
As of the writing of this document, most Windows VRML browsers capable of using EAI are not able to use the Sun Java plugin. Internet Explorer requires using the Microsoft JVM, and Netscape 4.8 and below use the Netscape internal JVM (Netscape 6 and greater cannot use the EAI). If you experience trouble viewing VRSpace worlds in Internet Explorer, make sure that the Microsoft JVM is enabled. To enable it, open Internet Explorer and go to Tools->Internet Options->Advanced. Scroll down to Java (SUN) and make sure the box beneath it is NOT checked. Turning off Sun's Java gives Microsoft's Java the go ahead to handle applets.
If the above solution doesn't work, or you are having the problem in Netscape, or other browsers, it is possible that your plugin does not support the EAI, an error occurred while installing the plugin, or additional steps are necessary to use the EAI with it. For example, an automatic download of Blaxxun 5.1 will not install the EAI, you must perform a manual installation to do so. The easiest solution here is to reinstall your plugin. If that doesn't work, check with the distributor to see if special steps are needed for installing the EAI. Don't forget, you can always ask for help at the Help forum of our sourceforge homepage.