HTTPS for subdomain internal error

Server
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1

Steps to reproduce
1. When I go to https://cloud.mydomain.com, I get internal server error

Expected behaviour
If I go to http://cloud.mydomain.com, it works fine, however this is not secure. It does also work fine if I go to https:// mydomain .com /cloud

Actual behaviour
The server encountered an internal error and was unable to complete your request.
Please contact the server administrator if this error reappears multiple times, please include the technical details below in your report.

More details can be found in the server log.

Technical details

Remote Address: REMOVED
Request ID: WGJVIK3@HDcAAHJCH8UAAARS

Is there anything I need to do to configure my custom subdomain to work?

This is a new install. Thanks!

2

Another thing to add, if I go to https://mydomain.com/cloud - it works correctly

My goal is it get it working by going to https://cloud.mydomain.com - which currently gives the internal server error

3

See:

and the FAQ category when getting an internal server error.