I get this error message when I try to update the plugin via the wordpress updater…
An error occurred while updating GP Premium: The package could not be installed. PCLZIP_ERR_BAD_FORMAT (-10) : Unable to find End of Central Dir Record signature
i assume that there is something wrong with your file or server.
We are experiencing a server issue, Tom is working on resolving this. Eduardo this may or may not be related. We will keep this post updated once we have a fix – thanks for your patience everyone.