You can actually still sign and trade, but sadly that won't fix the problem- believe me I have tried!!
If it's not just me experiencing this bug then it's pretty catastrophic, especially with no option of returning to an earlier save. Nothing worse than losing hours of progress... I am on xbox1.
As a further note, to improve the stability of my game I have turned injuries off. They seem to be bugged with the latest patch, with recurring injuries plaguing the league (seemingly due to the CPU failing to adjust the training regime of its injured players).