The latest version of AGESA ComboAM4 microcode that enables 3rd generation Ryzen support on AMD 400-series chipset motherboards has been deemed buggy and pulled from motherboard vendors. AGESA ComboAM4 1.0.0.3ABA (not to be confused with 1.0.0.3AB that's being widely distributed), was originally released to fix an application crash noticed with "Destiny 2." The microcode inadvertantly destabilizes PCI-Express on motherboards, with users of ASUS motherboards complaining of stability issues with the latest BIOS updates that include 1.0.0.3ABA.Peter "Shamino" Tan from ASUS commented that the company was under a tight schedule to push 1.0.0.3ABA out as BIOS updates, and didn't have the time to properly validate it. "We just got told to pull (was undergoing validation prior) 1003 ABA version," he said, adding the root cause of the problem being "that PCIE speed of BXB-C downgraded from gen4 to gen2,..." He comments "so its not surprising that bugs emerge since the source has hidden bugs that only gets unraveled with thorough testing. combine that with trying to get firmwares out in a tight time frame, kinda damn if you do (release firmware quickly) and damn if you dont (dont release firmware quickly) situation." It's interesting to note that in their BIOS update change-logs, quite a few motherboard vendors omit the full version string of AGESA. You may encounter ComboAM4 1.0.0.3AB being referred to simply as "AGESA ComboAM4 1.0.0.3."