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"
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And this one as well :
AdminTool \ Sessions \ Settings \ Open URLs on user side
must be disabled.
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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.