Unable to use dashboard_lookml() for lookml dashboards

[wsjk]

I use the Python SDK and until recently I could run sdk.dashboard_lookml("my_model::my_dash") and the response would contain a lookml attribute that was the entire lookml code of the dashboard as a string. Today I get this error when trying to run that code:

SDKError: 
    message:           An error has occurred.
    documentation_url: https://docs.cloud.google.com/looker/docs/r/err/4.0/500/get/dashboards/lookml/:dashboard_id
    error_doc_url:     
    error details:

The method does work, however, for user defined dashboards.

I've tried running code again on current SDK version (26.2.0) and tested much older versions as well (25.2.0) and still no dice. I'm guessing something changed further upstream to break this functionality?

[drstrangelooker]

Anytime the result is a 500, that indicates an error in Looker. Can you report this as a Looker bug please?