you have a valid ios distribution certificate on the developer website,but it is not installed locally,if your signing identity is installed on another Mac,you can export adeveloper profile on that mac and import it on this mac ,you can also reset your current certificate

certificate在當前電腦上沒有安裝好。你開發賬號中已經有了一個certificate，但是是在別的電腦上生成的，安裝在了那臺電腦上。如果需要在新的電腦上安裝certificate，需要在原來電腦kechain上用把certificate到出為.p12檔案，再把這個檔案匯入你當前的電腦，這樣你就可以安裝certificate了。