Error when updating woodmart theme & child theme for woodmart not appear

We want to update our fnbstores.com/my-old theme, but it appears error when updating.

Error - Update Failed: The package could not be installed. PCLZIP_ERR_BAD_FORMAT (-10) : Unable to find End of Central Dir Record signature

Plus our child theme not appear in the backends

Please advise how to resolved this issue as we need the child theme as soon as possible

Hi,

Contact with your purchase item author @xtemos right here as a comments

hope they will helped!