NextGEN Can't create tables

Hello, I have just bought Phomedia theme and the plugin NextGEN Gallery returns the following error when I activate it:

NextGEN Gallery : Tables could not created, please check your database settings

I have googled but any solution I have found has been useful for me. For example, I have DB_CHARSET with utf8.

I am using WordPress 3.7.1.

Could anyone help me?

Thank you.

Hello, I have already solved. I have reinstalled Wordpress and I have not modified the default configuration. Then, I have reinstalled the plugin successfully.