This same issue happened to my girlfriend once so now I understand what happened… I had my main account installed on a device and restored the game to a different account after doing this I could no longer restore my account back onto my device or any other device for that matter, nor can I use global chat. I remember when this happened to my girl her invite code also said _DEACTIVATED after it like mine does now.
In the future. The best way to get around that is to uninstall the game and reinstall it if switching GoW accounts.
Ya I figured that after in realized what happened, thanks for confirming that works
I tell you what tho… I love the support on this game! Already fixed my account, I better donates, seriously they deserve some coffee and donuts for the speedy fix