When I tried to upload images, all of them have "?" thumbnail. I am not sure why and how to fix it? Thank you,
Did you create your own WordPress instance, or are you using the Vultr one-click WordPress app?
Hello, I am using Vultr one-click Wordpress app. I managed to solve the problem by changing the permission folder and the files to 755.
Thank you for clarifying. We will attempt to reproduce this issue internally.
how you can changing the permission folder and the files to 755.
WordPress has an article on this issue.