Updating TSplus doesn't work and you get this error message:
Url On Client
Cannot open this web page remotely
\\tsclient\c\webtmp\ not found
Please make sure you did not enable this option from your AdminTool:
AdminTool \ Advanced \ Sessions \ URL on Client - Enable "tel:" protocol
value set on "No"
And this one as well :
AdminTool \ Sessions \ Settings \ Open URLs on user side
must be disabled.
Why?
Because your system is currently trying to open the update URL using URLOnClient instead of the normal way, so you need to disable it during your upgrade process.