UPDATE: According to Nuckles87, patch only affect first two boost missions. Costing you 8 stars at the most, so not as bad as previously thought.
New Wii U owners may not want to update too fast. It seems Sega’s first patch for Sonic and All Stars Racing Transformed has a glitch in it that stops some boost challenges from having checkpoints. Leaving you with no other choice but to fail the mission which leaves you stuck. However, there are some ways around it.
Play while it’s updating and finish the challenge. There’s no guarantee that there won’t be another glitched challenge, but it will get you past that.
Editor Nuckles87 has discovered that if you fail the mission four times on easy, it will let you pass to the next challenge.
If you just got your brand new Wii U. I’d recommend holding off on doing the system update until this game breaking issue gets a new patch of it’s own.