PositiveClicks on "[Plugin: WP-DBManager] Plugin could not be activated because it triggered a fatal error..."

Hello,

I am on a v3.9 Wordpress website with PHP v5.3.3 and MYSQL v5.1.73

Trying to activate (install) WP-DBManager
and the message appears:

Plugin could not be activated because it triggered a fatal error.

Any ideas?

Thank you in advance

https://wordpress.org/plugins/wp-dbmanager/