I got this error after updating my wiki recently. I tried to follow the steps under Installation from a .zip file, but I got a little confused by the wording.
So I installed the newest Widgest extension and then created a folder named 'smarty" (extensions/Widgets/smarty). Then I downloaded the newest Version of Smarty, unzipped it, and put the 'libs' folder in extensions/Widgets/smarty/libs.
But it didn't change anything, I still got the error message. What did I do wrong?