Preview screenshot problem during UI template upload

Hello
I’m Rajiv and when I uploading my first ui template project on envato theme forest, there are showing ‘preview screenshot could not process.’ What is the problem what i do?

I tried every possibility but not get results better and I see here are many users that are faces same problem when they are uploading their project.

I have uploaded a new item to CodeCanyon without any problem yesterday. If you are having issues, you could try to use FTP upload

Looks like you are trying to upload Template Kit.

Preview Screenshots:
ZIP file of images (png/jpg). You can named like home.jpg, about.jpg, contact.jpg, 1.jpg, 2.jpg, 3.jpg then make a .zip named preview-screenshots.zip. and try to upload that .zip.

Please try optimizing them - you may need to do it in Photoshop or similar first, then try running them through tinyjpg.com - the results should be under 1MB each.