please see the suggested workaround posted by @SimplyAS10 in this thread! please let us know if it works for you too!
one more thought on this approach: I'd still guess that the issue is related to something corrupted stored in the background of your lineups (even if the workaround did not work for everybody). I've faced a very similar bug in one of the previous promos and this approach worked for me too then. At the time, I could observe that the bug was probably related to the activated Superstar Abilities and/or x-Factors. When the game's code identifies too many active Abilities or x-Factors in a lineup (for whatever reason), this bug seems to occur. I would therefore try to either create a completely new lineup (as suggested by @SimplyAS10 ) and/or disable all Abilities and x-Factors. I hope this is helpful for you! Good luck!
as a sidenote (@lindros2018): yes, agreed! this approach is not a "solution" but just a workaround. I'd prefer a clean solution too but if a workaround allows you to at least receive the rewards of the Solos, I'd hope it is acceptable for you. But I have to say that I was very disappointed too when I was not allowed to play with my own lineup...
EDIT: I've seen similar reports in the EA forums too. I tried to inform the community managers about this issue.
