I’ve uploaded the image for the image slider(After installing the theme), but it’s not being generated at 2100×700 resolution. I then followed your advice here and installed the “Regenerate Thumbnails” plugin. When I ran that it regenerated the thumbnails, but didn’t do the 2100×700 resolution.
I manually sized it to 2100×700 in photoshop since I don’t want weird cropping/resolution things done to the image, then upload it to WP. When I go to the wp-content\uploads\yyyy\mm folder there isn’t a 2100×700 version there. If I copy the base file to end in -2100×700 it works.