Signals Notebook: When I try to set an experiment field as read only the option is grayed-out

If the type of 'Attribute' is does not allow read only or if the field configuration has not been set correctly, the 'Read Only' option will be grayed-out. By definition 'Text' fields can not be set to read only and list attributes need a 'Default Value' to be specified before the option is enabled.

Solution: Ensure the attribute type and field configuration are correct.