We’re in the process of updating the documentation for Zotero 5.0. Some documentation may be outdated in the meantime. Thanks for your understanding.
Security certificate errors in Zotero
Note: These instructions are only for use with security software that intercepts/scans HTTPS connections, a WebDAV server with a self-signed certificate, or an institutional network that monitors encrypted traffic using a custom root certificate authority (CA). You should never override certificate errors unless you understand the consequences.
Zotero does not currently provide a graphical way to whitelist self-signed certificates or custom root certificates, so you will need to copy files from a working Firefox installation.
If you use a WebDAV server with a self-signed certificate, you can open the WebDAV URL in Firefox, accept the certificate, and then copy the cert_override.txt file from the Firefox profile directory to the Zotero profile directory.
If you or your organization is using a custom certificate authority, which can be the case when using security software or connecting via a proxy server, it may be necessary to copy the cert8.db file as well.