I was testing Odoo 9 but i need a module that is only available on Odoo 8. I unistall the Odoo 9 and install the 8, but when i try to enter odoo appears the following message: 

Internal Server Error

The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

I try some thing to solve it but it dont work. Now i cant acces and don't have the odoo database.

Someone knows a solution for it? I try to create the database, but i don't know how to do it withowt the odoo database manager.