From the [url=https://forum.graphene-theme.com/graphene-mobile-neo/frequently-asked-questions/]theme’s FAQ[/url]:
Quote:
When trying to update the theme, I received an error message containing “PCLZIP_ERR_BAD_FORMAT (-10)â€. What broke?
Nothing. 99% of the time this is due to the API Key being missing from the theme’s options page. Make sure that you have inserted the API Key for the product that you have received after your purchase in the theme’s options page, and then try performing the update again. You may need to try performing the update twice more since WordPress caches update check and response.
If you have lost your API Key, you can retrieve it from your [url=https://forum.graphene-theme.com/your-account/]Account Page[/url].