Can I make a field read-only in a transition, or all transitions?

[Phil Bustin]

Related to that, I have still not succeeded in removing None from the options in a single-selection field, although I made it Required in the Custom field configuration.

[Mikael Sandberg]

You would need something like Scriptrunner and Behaviours in order to make the field read-only.

And regarding the None option, the only way to remove it is to set a default value for the custom field.

[Phil Bustin]

For a single selection field, I set a default value and I made it required in a Field Configuration I created, in a Field Configuration Scheme I created.  I'm not convinced I connected everything as it should be, because the field still contains the None option and its label is not followed by an asterisk in transition screens.