Hi @steambrook,
The issue seem to be with Web Server rather than Theme itself.
We looked into this error (505) a little further and found as below:
Why it occurs
The Web server does not support, or refuses to support, the HTTP protocol version specified by the client in the HTTP request data stream sent to the server. The HTTP protocol has various versions identified as major and minor, e.g. version 0.9, 1.0 or 1.1. The server is indicating that it is unable or unwilling to complete the request using the major version provided by the client.
Fixing 505 error code
The only option to fix this error is to upgrade the Web server software to the higher version. Because the lower versions provide poorer security and performance than newer versions of the protocol.
Source: https://100pulse.com/http-statuscode/505.jsp
Hope this information helps.
Thanks.
ThemeGrill