Internal error

[balagab]

I installed the plugin, everything is ok in the administration/plugins but if I made any change on an issue, I recieve internall error.
Environment:
Redmine version 2.5.0.stable
Ruby version 1.9.3-p545 (2014-02-24) [x86_64-linux]
Rails version 3.2.17
Environment production
Database adapter SQLServer

I modified the plugin name to: redmine_email_notification_content_filter

Thanks