Assigning user variables in forms through the ‘use context’ option

Summary:

In our EPM Planning instance we have a user variable set up ‘uEntity’ which is currently has the ‘use context’ option set on it.

As I understand, this means that a user cannot set a value for that variable and instead it is dynamically populated from another source when a form is opened.

When I try to open a form that uses that variable I get the following message “unable to open the form because it uses the use context option to dynamically update the user variable value for Entity dimension”

For reference, the form in question is coded up to use the variable, which doesn’t have a default value set: