WordPress theme installer repeats "Are you sure you want to do this? Please try again."
If you are installing your theme from the WordPress theme installer, but get a message that says Are you sure you want to do this?, most likely your web server is configured with low PHP settings that only allow a certain size ZIP file to be uploaded via WP admin.
Most hosting companies configure their servers to only have the maximum file upload size limit at 8-10 MB, some are less. So if you get this error, your web server is rejecting the upload due to the overall size of the theme zip file. WordPress, unfortunately, gives you a rather ambiguous message in response. This is not a theme issue or a bug.
To Solve The Problem
- You can get your web host to increase your PHP limits so a larger zip file is allowed to be uploaded. They will know which limits to set if you explain the issue.
- You can upload your theme via FTP. It is very easy and efficient. Or alternatively, you can install the theme via the wp file manager plugin