Problem for Plugin Architecture 2.1

[David927]

Hi
I am a new for cacti. After install plugin Architecture v2.1, there are

Reset() [fuction.reset]: passed variable is not an array or object in /usr/share/cacti/site/lib/functions.php on line 146

Variable passed to each() is not array or object in /usr/share/cacti/site/lib/functions.php on line 147

show on my cacti. And cacti don’t draw the graph. There is only a template on the screen. It seems like no data can be draw.

Please tell me how to fix that

Thanks
Cacti Version - 0.8.7b
Plugin Architecture - 2.1
Ubuntu 8.04.1