Thread:Extension talk:Widgets/Purging Page With Widget Gives Notice/reply

I found what's wrong. Your code is buggy.

In WidgetRenderer.php line 143, the code should be return $matches ? base64_decode( $matches[1]) : ''; rather than return base64_decode($matches[1]); because, when nothing is matched, the $matches will be, and hence 1 of   is not set.

I thought you have not turned on your E_NOTICE tag on PHP when you were developing, so you have made such buggy code, and cause problem to your users.