<< Solved >> Garbled Screen on HD 4600 Graphics after Catalina 10.15.5 update

[Namok88]

Hey guys, i managed to fix this by downloading ubuntu live CD and completely reformatting the EFI partition, then i deleted the partition and recreated it using gpt.

Glad you fixed it! (you can edit your post's title and add the "Solved" prefix)

But you could have done that with Disk Utility too.

View >> Show All Devices >> select your main drive >> Erase >> NAME/APFS/GUID