In rare cases, a "field not editable" error is returned when updating radius values.

[travisval]

When attempting to merge multiple centre points together, a "field not editable" exception is sometimes raised. This appears to be data specific, but it is unclear as to why. Currently the only workaround is to manually update the curve information.

This issue is reproducible on versions 10.4, 10.3.1, and 10.2.2. It has not been reproduced on 10.1.