Cant check integrity

I would like to install e with easy installer but i have some struggle.
Instead of downloading os it writes cant check integrity. OEM allowed, usb debbuging allowed. Drivers are installed.

Hello @kaBe what is your device ?

My device is Samsung S8

Are you sure it is a “dreamlte” internationnal model SM-G950F or SM-G950FD ?

i checked device info in setting and I have SM–G950f

I wonder how new is the phone, have you had it online both by Wifi and SIM card?

If the phone is new or newly refurbished you might, perhaps, suffer from KG or RMM State Prenormal ?

In light of your reply @kaBe see also Carrier locked bootloader in the same article. Is any KG or RMM seen in your Download mode screen?

its my old phone. i had it online by both. but its some T-mobile distribution with their apps and logos.