I just got the same error message:
Updating Theme Web Minimalist 200901 (1/1)
Downloading update from https://www.ads-software.com/extend/themes/download/Web-Minimalist-200901.1.1.zip…
Unpacking the update…
An error occurred while updating Web Minimalist 200901: Incompatible Archive. PCLZIP_ERR_BAD_FORMAT (-10) : Unable to find End of Central Dir Record signature.
