Can't save a psd as a png, png suddenly not available in dropdown

[starbird]

At my wits end. I need to resize two dozen shirt images. I have been saving as psd and png. Now I don't see png in the dropdown. Why? Where is it? This image is no different than the others.... same size etc. Here is what I'm seeing.

How do I get it to offer up a png?

HELLLLLLLLLLLP!

I hope someone knows the answer....
Thanks

 

[starbird]

I just found it. It needs to be RGB and was CMYK for the printer. Whew.