I managed to finish 4 of each color but couldnt access any of the last challenges.

Same Here

Have the same issue both on Windows and iOS.

Got the same error while trying to complete the color challenges

Same here

Suggestion: Fix. Or give option for auto complete.

Color challenge - all complete except final stage of white. Does not allow completion. Gives following error:

Network Error - Unable to Join Event. Please try again later

Does not allow to play and find regular pvp matches. Play defaults to color challenge, but match can not be started due to above error. also can not receive 2 gold wild card reward due to this.

I have a suspicion this is due to editing the deck. Make starter decks for color challenge non editable or no edit versions strictly for this mode.

same, always says "unable to join event"

Can't play a color challenge game, Network Error immediately pops up. Samsung S21 Ultra 5G

Can't play a color challenge game, Network Error immediately pops up. Samsung S21 Ultra 5G

See this one:
https://feedback.wizards.com/forums/918667-mtg-arena-bugs-product-suggestions/suggestions/44287815-color-challenge-network-error

Same problem here both on iOS and Windows App. Can't finish the blue color challenge.

same

I have the same issue too. It's really troublesome.

El problema que tengo es que no puedo completar el desafio de colores (color challenge en ingles), complete el desafio casi al 100% lo unico que me falta es el ultimo combate del desafio de color rojo, aqui dejo las imagenes del problema, cada vez que intento hacer el desafio me aparece un cartel de error de red aunque el error no se presenta en ningun otro desafio o modo que haya probado hasta ahora, tambien probe verificando mi conexion de internet pero no hay ningun problema con la conexion ya que probe jugar con otra conexion y el problema persiste, me gustaria terminar el desafio ya que llevo atascado en esa mision varios dias, los mazos dual que tengo son de jump in, aunque me limita demasiado la mision y el tener los mazos de un color.

The problem I have is that I can not complete the challenge of colors (color challenge in English), I completed the challenge almost 100% the only thing I need is the last match of the challenge of red color, here I leave the images of the problem, each every time I try to do the challenge I get a network error poster although the error does not appear in any other challenge or mode that I have tried so far, I also tried verifying my internet connection but there is no problem with the connection since I tried play with another connection and the problem persists, I would like to finish the challenge since I have been stuck in that mission for several days, the dual decks that I have are jump in, although it limits the mission too much and having the decks of one color.

Blue mastery will not connect at last part say network error.

Cada vez que intento terminar el desafío de color, aparece un error de red, solo me falta la última partida de mazo blanco para terminarlo.

Everytime I try to finish the color Challenge I get a network error, I am only missing the last White deck Match to finish it.
I attached the error details

Cannot complete the color challenge ! This is my last match

We now are on the 22nd of october, this bug has been around for almost a week for me and nothing has been done. When I tried reaching out to the support all they did was send me a link to this post lel.

Same issue here with last match of red and white. Really want to complete color challenge to unlock the dual color starter decks