这可能与您的问题无关，可能没有解释，但是一名员工遇到问题，他的iPhone不一致地接受ICS日历邀请，并且正在接收这个邀请数据是过时的消息，当它不起作用。经过多次尝试尝试和错误，结果是如果iPhone连接到wifi，它将给出此邀请数据已过期的消息。如果它仅连接到电话运营商网络，它将成功添加该事件。

This may be irrelevant to your issue and probably explains nothing, but an employee was having an issue with his iPhone inconsistently accepting ICS calendar invites and was receiving "this invitation data is out of date" messages when it would not work. After multiple attempts of trial and error, the result was that if the iPhone was connected to wifi, it would give the "this invitation data is out of date" message. If it was connected only to the phone carrier network, it would successfully add the event.