Problem with updating theme

Hi, I wanted to update my theme but receieved the following message: The update process is starting. This process may take a while on some hosts, so please be patient. Enabling Maintenance mode… Updating Theme Catch Kathmandu Pro (1/1) An error occurred while updating Catch Kathmandu Pro: Update package not available. Disabling Maintenance mode… All updates have been completed. I was trying to update to your new version 4.0. What should I do? Kind regards Helena