Kicked from UT when submitting any SBC: “Error communicating with the servers.”

Yesterday I completed several SBCs — around 100+ 78x3s — since I was grinding them with the large number of cards available from Winter Wildcards. Before going to bed, I tried to complete the Base Icon or TOTY Icon 87+ SBC, but when I went to submit the last squad, I got the following error: "There was an error communicating with the football ultimate team servers. Please try again." 

I turned off my Xbox, played a match, closed the app, etc., but the error persisted. At first, I thought it was just a server issue, so I went to bed, but now that I woke up, the error is still there.

Can someone please help me? With the amount of new content out, not being able to complete SBCs puts me at a disadvantage. I’d really appreciate any assistance — thank you very much.