If you installing plugin Key and receive such error: PCLZIP_ERR_BAD_FORMAT (-10): Unable to find End of Central Dir Record signature. For sure you have Safari browser. By default it’s unzipping downloaded archives.
Solutions: 1) Turn off automatically uncompress option. Follow instruction below.
When Safari downloads a .zip file, it automatically uncompresses the file when the download is finished but the .zip file is then no-where to be found. Sometimes you just don’t want Safari to do this.
There’s a simple way to stop this. If you would rather Safari just download the .zip file and leave if for you to decide what to do, go into the Preferences and simply untick the option Open “safe” files after downloading.
2) Try to use another browser for key download. For example Chrome or Firefox.