In Google Cloud Platform I have enabled the Apps Marketplace SDK to publish a sheets-on to Marketplace.
In APIs & Services > Apps Marketplace SDK > Publish I am unable to upload a screenshot. I keep getting Not saved.
see here:
I am using the correct size screenshot and have tried many different sizes and image types. ex. 640x400, 1280x800 all the recommended sizes. I have used png and jpg.
I can't click the publish button until a screenshot is uploaded. This is weird because I was able to upload an image for application banner without issue (as shown in the image above).
Any ideas why I am getting this Not saved message?
You have to upload your screenshots into the Chrome Web Store Developer Dashboard. Look at this FAQ.
Please see the warning at the top. The Publish tab should not be used yet for add-ons created in Apps Script (Docs, Sheets, Slides and Forms). Those details have to be filled in Chrome Web Store and after about 48hs the publication should be available in G Suite Marketplace.
The G Suite Marketplace team is working on simplifying the publishing process and in the future it won't be required to publish in Chrome Web Store.
来源：https://stackoverflow.com/questions/51013733/unable-to-upload-screenshot-image-to-google-marketplace