Merge error - initialize source templates

[BonnerBL 0]

I'm trying to merge two datasets. I get an error message that the merge cant proceeed because ther eare one or more templates in the datasets that aren't standard. Im supposed to 1) set the source citation to custom (I did that) and then 2) go in each dataset and initialize the sources. I checked help and it says to go to Tools - Source Types and click on the dataset. An initialize button is suppose toi apepar. It doesn't. Help please..

[Terry Reigel 0]

You should see it at the bottom of the group of buttons on the right, as shown in this screenshot:

 

If you don't see it there, what buttons do you see on that screen?