When using the Classification toolbar's Training Sample Manager tool, the "Merge training samples" option is unresponsive.
Detail: I'm trying to merge an exported subset of a polygonal landcover dataset in order to use it as training data for the classification tool. (For example, I exported conifer categories. When I import the new conifer export to the Training Sample Manager, the manager tool still breaks the conifers out into multiple categories (spruce, hemlock...) that I'd like to merge into one training sample.) I select the categories merge, which are highlighted. The "Merge training samples" button is not grayed out and animates when it's clicked as if it's working. But nothing happens. There no indication that it's working (no cursor change, no notification from Arc). I've tried restarting the program with nothing else running. It's not crashing, just not working.
The attached image is the exported polygonal layer, its attribute table, and the Training Sample Manager after the layers been imported as training data, selected, and I've attempted the merge.
I seem to be missing something obvious. Any help is appreciated. Thank you in advance!
