Early registration message for Challenges that are active but haven't started yet

[ajefts]

Friendly message for challenges that are active but haven't started. Currently if you activate a challenge but it has a future date, you get a "challenge doesn't exist" error message. It would be nice to have a page that instead displays something like "You're early! You can begin registration for this challenge in X hours"

[ajefts]

Link to feature: https://tcprod.productboard.com/feature-board/planning/features/3753214

[Oanh-and-only-Oanh]

@ajefts, we're not able to reproduce the "challenge doesn't exist" error message. Please check this challenge, which is activated now but registration start time is in the future. https://www.topcoder.com/challenges/30113418/?type=develop

[ajefts]

Ok. This was reported by the delivery team, but I'm not sure exactly which individual. I'm pretty sure there are cases where the "challenge doesn't exist" message does appear. Maybe we can find those cases and smooth out the experience?