Error when opening applets

When opening Mapper or Process Designer, if you get the below error "Incorrect URL: null" then this is how you can fix this problem:

This error is a java cache issue. It usually happens when there are different versions of Adeptia installed on the same machine.

Please clean your java cache.
1. Go to Control Panel, double click on Java console
2. Click on Settings
3. Click on Delete Files > Ok
4. Then Ok on the main window.

Now open the applets.

You may also see the screens below: 

- Unable to launch the application

- JAR resources in JNLP file are not signed by same certificate