but until the release of the new profiles function you have got not solved the problem, that for some profile patterns it’s not possible to add a vignette. It's also still the same in the new major version.
The bug is shown when the amount of the vignette is 0. Select another profile, like Modern 03. Try to change the amount value for vignette.
A work around is to add a vignette with another working profile, change to the not working profile and change the value for the vignette. This is needed
When do you want to fix the bug?
- reset the develop settings
- select profile 'Modern 03' (with some others it's the same)
- try to change in the effects the amount value for Post-Crop Vignetting