Unexpected error about Burn Redeem(Json file error)

[MrMisang]

Big Burn&Redeem worked well for this artwork ;
https://app.manifold.xyz/br/1-999-TheSurvivors
Thanks a lot!

But I have to closed the contract with setting end date(time) - to apply it at homepage.

But when I tried to set end date and sign the tx, below error occurs.

Thanks for your support!

[MrMisang]

It solved but I don’t know why and how.
(Same error happened once last time)

[lyndo]

Thanks for letting us know!