I am using filters such as glow and blur filters in my app with packger 2.6. The filters break and do nothing.
Switching to CPU makes filters work, but makes everything laggy. How do I make the filters work in GPU?
They don't work in GPU. They have been disabled, presumably because of performance issues.
To get the same effect add your filters in CPU then take a snapshot of your clip and store it as a bitmap to use in GPU. Use this bitmap from then on. You'll have to get fancy if you have timeline or other animation.
See BitmapData.draw