Can’t swap error - help

I just bought an lm level 12 robert pires but when I am trying to swap him with the existing lm it doesn’t work. I can even add him on the substitute lineup or playing 11 at any position. Please help as if I sell him now I will lose a huge amount. I can add other players in the lineup without any issue and I can see robert pires in my players list. My UID is 

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