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Make sure to add the H2 jar file to the classpath environment variable. If you are using an IDE like NetBeans, add the H2 jar file to your project libraries.
A few things cause this exception:
1) Check if you have all jars and if they're in the correct path.
2) Your classpath might be broken, you can define it in the command line with
java -cp yourClassPathor at your IDE if you're using one.
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