Hi,
Please first ensure that Camelot is running outside of the ".zip" file downloaded.
1. Close Camelot completely;
2. Ensure that the ".zip" file for Camelot is extracted to its own folder.
3. Run Camelot from the new folder.
If this is done, and you're still receiving the same error, it suggests that for some reason Camelot is not able to find the Java program. This can be configured to address the problem.
1. Open Camelot, and navigate to Settings -> Advanced settings -> Installation location
2. Click the button to change the location, browse to the folder that you're using to run Camelot, and click "OK"
3. Navigate to Camelot and click "Start"
If set correctly Camelot should find the Java file and start correctly.
Hope that helps,
Chris