Internal error in liferay

I’ve been working on Liferay 6.0.6 and Vaadin 6.6.4.

When I deploy my application, I get Internal error as-

Internal error
Please notify the administrator.
Take note of any unsaved data, and click here to continue.

Previously, everything worked fine. But when I redployed the application all of a sudden I started getting this error.
Even if I click on the “click here” link in the error, I keep getting the same error. I do not get any exception, if I debug the application and also there are no stack traces printed.
I dont think this error appears because of any problem in the code.

What might be the problem ? Can somebody please enlighten me?

I was able to find out the problem. In one of the domain classes in service, equals and toString methods were implemented wrongly. After correcting them, everything worked fine.

Hi Rasiya, Can you help me, I am experiencing the same problem when using selenium. I can’t figure out what is happening. When I freshly started my server as well as selenium it works fine. But after that I will get the error: Internal Error please contact your administrator. So I need to restart servers, clear cache, and sometimes even eclipse to make it work again. Thank you!