Two days of media previews of the world’s tallest water slide have been canceled and the attraction’s scheduled opening Sunday is in question because of problems with its conveyor system.

The 17-story, 168-foot-tall water slide is called Verruckt — German for “insane.” Schlitterbahn Waterpark spokeswoman Winter Prosapio says the conveyor carries 100-pound, four-person rafts to the top of the slide in Kansas City, Kansas.

Verruckt was to open May 23, but that was moved to June 5 so more testing could be done and then pushed again to June 29.

Guinness World Records certified it as the world’s tallest water slide in April.

Another highly anticipated attraction, SteelHawk at Kansas City, Missouri’s Worlds of Fun, also hasn’t opened. It was to be ready May 24.