Why cant I link a CAPA to other CAPAs?

In order to be able to link a CAPA to other CAPAs, this setting must be enabled in Module Settings:

1. Go to CAPAs > Module Settings.
2. Click in Signature Settings.
3. Per default, the Linking CAPAs to CAPAs switch is turned OFF, turn it ON if you would like for users to be able to link CAPAs to other CAPAs in the system.