Updated June 9, 2016
This article addresses the following error that is displayed when attempting to publish third-party updates to your WSUS server:
Verification of Signature failed for file:
Run Microsoft MMC and add the snap-in for certificates for the computer account on the WSUS and the Patch Manager servers.
The certificates should be in the following:
On the WSUS server, the certificates should be in the WSUS certificate store.
If the steps in Solution 1 does not help: