Here's the quote from the latest release notes for the Z620 BIOS update to 3.94, and the E8300 uses the same type of BIOS and updates (not same version, of course). We here know what "fail to boot" means:
The following fixes have been made in BIOS version 03.94:
-Fixes an issue where system could fail to boot after upgrading to Windows 10, version 1803.