Alex, please post your hibernate.xml.cfg. There is a CODE button below the Add Reply button, make sure you put your xml within CODE tags so that your indentation will remain in your post, and make it easier for us to read.
I want to see if we can spot the problem. I have some guesses. 1) the version of Hibernate you are using versus the package of the Dialect classes. 2) Some single character error somewhere in your HTML.
Basically the code in Hibernate that has the error was first getting a
String value from a Properties object passed to the method. These are Properties that are set in the hibernate.xml.cfg
So if that is null, then it tries to find the Dialect another way which is also failing, but I don't think that the dialectName var should be null.
Mark