If you are installing your theme from the WordPress Dashboard and receiving a message that says “Are you sure you want to do this?“, most likely your WordPress install has a prohibitive maximum file size for uploads.
The size of theme ZIP file can be about 30 MB in size. So if you get this error, your web server is rejecting the upload due to the overall size of the file. If you want to know what your site’s upload limit is, you can visit Media -> Add New. Below the upload box you will see “Maximum upload file size” with a number next to it, in megabytes.
There two ways to solve this 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.
These are recommended PHP configuration limits:
- memory_limit = 128M
- upload_max_filesize = 64M
- post_max_size = 64M
- max_execution_time = 300