Family Historian User Group

On the Census tab of my Property Box it doesn't show details for the 1939 Census.
It doesn't appear to allow a new item so I thought I would sacrifice one of the Electoral Roll records.
I click one of the Census entries and copy the Data Reference INDI.CENS[year=1871].DATE
I then click Electoral Roll 1 and paste the entry above into the Data Reference and replace 1871 with 1939.
I get the error message 'Data Reference is invalid, or not valid for this context'
What am I doing wrong? - is there another way to do this?

Martin, first a little housekeeping. Please update the Family Historian Version in your Profile on the right.
Click your username martinreed top right of this web page and choose User Control Panel.
Then on its Profile tab, select your Family Historian Version, and scroll down to click Submit.
Then it appears to the right of your postings, and we don't have to guess.

You can add a new tab item, but must untick Show most commonly-used items only bottom left of Customize Property Box.
If you click the Help button in that dialogue it explains all about that.
Then you can use <Custom Item> to add items for Register 1939 modelled on the Census items.
Not sure why you get that error message as in FH V6 it should just warn that it will be read-only and ask to Proceed anyway?.
Double-check there is nothing else in the Data Reference box other than INDI.CENS[year=1939].DATE

Mike,
Thanks very much for your prompt reply.
Worked fine.