xiaomi update miui 8 miui 7

Hello guys, First I have to say Im new on this site and I dont know anything about Miui. All I know is that the current Miui Version is 7.2.5.0 (Miui by Xiaomi.eu) Stable, Android Version 5.2.0. Cant update by the Mi Update OTA Service. I get an error alert "couldn't verify update package"...