Could you also post the change file that got generated? Did it execute successfully? Did you change just one field?
Also note that changing fields type to completely different one might result in loosing data as there is no conversion involved so it is up to the database what it does with it.
Understood. To be clear, I am not planning to use this option myself.
I just trying DB Manager for the first time, so testing different things and reporting all unusual and potentially troublesome issues.