Does this mean we have to input data again?
Or is it simply the name of the column that is changed, but the data remains ?

Hi
There is no data loss as jD handles the 'conversion' of the 3.2 to 3.9.  Just to be clear, you do not need to re-input any data.

The implication is just on 'other' extensions, that is extensions not included with jD, that provide compatibility with jDownloads.  As far as we are aware all known 'other' extensions have been upgraded.
Colin
Please see
https://www.jdownloads.net/documentation-for-v3-9-beta/getting-started-v3-9/upgrading-from-jdownloads-3-2-to-3-9

In principle I think the data remains and you just have to update the column, I think it was an update failure ...

@Kaze30
there is nothing for the user to do - jD does all that is necessary

Colin