Settings, tab Tasks, field Task troubleshooting URL, the description says:

Url
 pointing to the task troubleshooting documentation. It should contain 
%{label} placeholder, that will be replaced with normalized task label 
(restricted to only alphanumeric characters)). %{version} placeholder is
 also available.

It allows me to change the value to something that is not URL, like "xx".

Then, when I try to set something correct, like

https://access.redhat.com/solutions/satellite6-tasks#%{label}
, which is the default value, it doesn't let me, showing the following:

Error updating setting: undefined