Unable to activate Gedit plugin

Hi everyone

I downloaded the multi-edit plugin for Gedit from this link:
Multi-edit | Jon Walsh

I copied all the files in ~/.gnome2/gedit/plugins/ as described in the website but I can't activate the plugin. I can see it but I can't activate it in Gedit preferences.

Does anyone come across the same problem and found a solution?
Any suggestions please?

Thanks a lot