Certificate Problem

ibihibi

Since last weekend we have a certificate error with connecting Zotero via WebDAV to a Nextcloud-Server which worked for months. The certificate is a trusted one (not self signed). Browsers do trust it when requesting the WebDAV URL but Zotero does not.
I've running the latest Version of Zotero 5.0.30. (With Zotero 4, that I installed for testing, I wasn't able to replicate the error.)
According to following postings
https://www.zotero.org/support/kb/ssl_certificate_error
https://www.zotero.org/support/kb/cert_override
https://www.zotero.org/support/kb/incomplete_cert_chain
I tried to whitelist the certificate, even if the certificate is trusted, with partial success: It works now for administrator, but not for another user on the system (after copying the cert_override.txt into its Zotero profile)
On a notebook we experienced an additional interresting issue: The certificate was accepted when connecting over the wireless adapter, but not over ethernet.

Are there any known problems with certificates and Zotero 5 and what else could I try to solve this issue?

Thanks in advance for any hints!

dstillman

Yeah, don't whitelist it if it's a trusted cert chain.

Can you clear the cert_override.txt file and provide a Debug ID for a Verify Server attempt that fails?

The certificate was accepted when connecting over the wireless adapter, but not over ethernet.

This strongly suggests a MITM issue.