No token established...

After i press SIGE parameters button i get...

No token established! You must enter a token to restrict the possibility to access the file from the outside. Without this security measure, someone else could read the folder structure of the server from outside the plugin. Please set up in the plugin settings.

Im on 1.7 joomla and i cant go on 2.5 right now, or the problem is else were ?

thx

luka