Could you provide an example of what you are trying to do?
If you are trying to import files from your photo Gallery, tap on the "Images" icon and select the "On my iPad" option. Also you can download assets from your Adobe Creative Cloud Libraries by tapping on the "Images" icon and selecting the "My Files" option.
Hope this helps,
I was allowed to only select pictures from my image library if they were available on the first screen of my library. If I wanted to effect an image further down in the library, I was not allowed to select it. In any event, an application that doesn't perform as advertised is of no use to anyone. I've since deleted the application.
Based on the title of your post, seems like the application you were using was "My Sketch". This forum is for Adobe Photoshop Sketch: Adobe Photoshop Sketch on the App Store on iTunes. If you have not tried Adobe Photoshop Sketch, please give it a try. Hopefully, it will be a better fit for what you want to do. You are allowed to select any of your images from your photo gallery.