Can't download repair patch for UE 4.27.1

Hi, I have a problem with UE 4.27.1
After opening project or creating a new one my UE start to flicker and even get black in the first few seconds.
I’ve tried updating GPU drivers and after that running a Verification of UE version.
I found a small problem and want to download a small 1,1MB repair patch but it can’t start a downloading and then show an error with connection (after that I’ve even tried to disable firewall and set default setting for my IP and DNS).
Noting work… Do you know some solution for this flickering problem or repair problem?
Thanks a lot.