If you got this message while installing your theme from the WordPress panel, it usually means that you have a too low upload limit size on your server.
In order to bypass this issue, the quickest hack is too upload your theme manually.
Please follow along those steps:
- Extract (unzip) the Woffice theme folder downloaded from ThemeForest Connect to your web server using any FTP client (eg: FileZilla, CyberDuck),
- Upload the extracted folder within the wp-content > themes folder on your server.
- Head over to your WordPress admin panel > Appearance > Theme section, and activate Woffice.
It is an environment issue so feel free to ask you host provider to fix it for you. They just need to increase the upload limit.