esxupdate.log:
1998-01-22T08:31:19Z Er(11) esxupdate[2103488]: vmware.esximage.Errors.InstallationError: VMware_bootbank_esx-update_8.0.3-0.60.24585383, VMware_bootbank_loadesx_8.0.3-0.60.24585383: Failed to setup patcher for upgrade: ('VMware_bootbank_esx-update_8.0.3-0.60.24585383', 'Could not find a trusted signer: certificate is not yet valid')
8.x
Certificate error is tied to the incorrect system time.
Use KB Verifying time synchronization across an ESXi host environment to sync the system time of the ESXi host.