Nextcloud 12 and Collabora - cURL error 60


i have problems with Nextcloud 12 and Collabora in an docker container. Running with Debian 9, PHP 7.0 and Apache2.
I have installed Collabora with the installation guide and Nextcloud ist running fine with an wildcard certificate for our company domain
Nextcloud has a vhost file for and Collabora has a vhost file (like in the guide) for

But Collabora cannot open any file in nextcloud (internal server error) and in the nextcloud logs ist this error message after opening a file:

GuzzleHttp\Exception\RequestException: cURL error 60: SSL certificate problem: unable to get local issuer certificate

Where is the mistake?

Thank You

This means the certificate you have installed on the collabora server is not valid (self-signed).
Either disable certificate verification or installed a valid certificate.

Thanks. It was the intermediate certificate thas was missing in apache.

How do you install the intermediate certificate??? I installed a certificate from certbot, shouldn’t it be working?

Was this figured out??? I’ve installed all the certs but still getting an error, is the app store i’m using wrong?