An unknown error occurred

I have got same error.Please let me know what to do ?

same problem here.

Same here.

We are also getting the same error. Would there be a solution available for this issue. Please let us know.

Same problem. Can anyone help?
cc: @demoive

Yes, same here :/

same here

Same problem here ??

Hey folks! I had the same problem and somehow it worked when I uploaded a logo to my Instant Articles Default Model. I haven’t check this out before because I wanted to go fast through the process. Now everything seems to be working and I could send my articles to the Facebook’s team review. Wish this message can help you all. Cheers