WSUS | error 800B0001

WindoesUpdate.log says:

Digital Signatures on file C:\Windows\SoftwareDistribution\SelfUpdate\wuident.cab are not trusted

 

Be sure your WSUS installation is fully patched:

https://wsus.de/de/FAQ -> 44

WSUS auf Windows Server 2008 / 2008 R2
WSUS 3.0 (RC):	Build 3.0.6000.318
WSUS 3.0 (RTW):	Build 3.0.6000.374
WSUS 3.0 (SP1):	Build 3.1.6001.65
WSUS 3.0 (SP1) + KB954960:	Build 3.1.6001.66
WSUS 3.0 (SP2 Beta):	Build 3.2.7000.84
WSUS 3.0 (SP2 RC):	Build 3.2.7085.146
WSUS 3.0 (SP2):	Build 3.2.7600.226
WSUS 3.0 (SP2) + KB2720211:	Build 3.2.7600.251
WSUS 3.0 (SP2) + KB2734608:	Build 3.2.7600.256
WSUS 3.0 (SP2) + KB2828185:	Build 3.2.7600.262
WSUS 3.0 (SP2) + KB2938066:	Build 3.2.7600.274
WSUS 3.0 (SP2) + KB4484071:	Build 3.2.7600.307
WSUS auf Windows Server 2012 / 2012 R2
WSUS 4.0 (RTM):	Build 6.3.9600.16384
WSUS 4.0 + KB3095113 Unterstützung von Windows 10 (keine Upgrades!):	Build 6.3.9600.18228
WSUS 4.0 + KB3159706 Unterstützung von Windows 10 (auch Upgrades!):	Build 6.3.9600.18324
	Build 6.3.9600.18838
WSUS auf Windows Server 2016
WSUS (RTM):	Build 10.0.14393.x