This error may be seen when you are uploading a file inside WordPress which the system expects to be a .zip file type.
The package could not be installed. PCLZIP_ERR_BAD_FORMAT (-10) : Unable to find End of Central Dir Record signature
If you see this message, make sure you are uploading the original zip file, not an unzipped folder. You can re-zip your file, but the content must be the same, and the filename must be the same as the original download.
Safari opens zips
