It has been found that the Software Delivery distributions may fail, if the target computers have the ENC client disabled after having it enabled in the past.
Why my Software Distributions fail if I disable the ENC client on computers which had it enabled before?
At the moment of writing this Technical Document, this is a known problem but there is no fix for it yet.
However, it can be worked around by making the ENC client point to a non-existent gateway server to keep it running.
The following command can be launched on the workstations for such a purpose:
encutilcmd client -state enabled -server 127.0.0.1 -start
This way, the ENC client is on, but pointing to an non-existent ENC Gateway avoiding the network traffic out the client itself.