I tied my water to an func_water_analog to make the slime rise, the slime did rise and looke great, until today. Now it rises but it is invisible. If i tie the water back to a world brush it becomes visible again. What has happened.

using that setup is really buggy in portal 2

So is there another way to make the water rise. I have tried to tie the water to func_brush, but the water still does not render, it is there, you just cant see it.

I gave up on rising water in my map. Good luck to you!

I gave up on rising water in my map too. I posted a forum but had no luck other than getting a few posts from people high up in the TWP community (WinstonSmith, Pete and Vordwann) but apparently still learning to read.