"An error occurred" at first login, after setup on the home screen

After resolving the reverse-proxy issues I went to deploy on production. To the best of my knowledge I have followed the same steps as ironed out in dev. It is depoloyed behind the reverse proxy at "/". Metabase guided me through the setup screen and seemed to work correctly. I chose to skip connecting to my DB during the install to do that later. When it tries to render the home screen for the first time I get an empty white page with the message "An error occurred":

There are no messages in my browser console, and no errors in the Metabase log. I enabled db & server tracing with MB_NS_TRACE="metabase.db,metabase.server" and got a few more messages, but nothing stands out to me. These are the messages that are generated when I refresh the browser window:

Jan 29 10:04:09 apa metabase[17168]: 2021-01-29 10:04:09,297 DEBUG middleware.log :: GET /api/database 200 28.7 ms (4 DB calls) App DB connections: 0/4 Jetty threads: 3/50 (4 idle, 0 queued) (45 total active threads) Queries in flight: 0 (0 queued)
Jan 29 10:09:23 apa metabase[17168]: TRACE t554: (metabase.db/db-is-setup?)
Jan 29 10:09:23 apa metabase[17168]: TRACE t554: => true
Jan 29 10:09:23 apa metabase[17168]: TRACE t555: (metabase.db/db-type)
Jan 29 10:09:23 apa metabase[17168]: TRACE t555: => :mysql
Jan 29 10:09:23 apa metabase[17168]: TRACE t556: (metabase.db/db-is-setup?)
Jan 29 10:09:23 apa metabase[17168]: TRACE t556: => true
Jan 29 10:09:24 apa metabase[17168]: TRACE t557: (metabase.db/db-type)
Jan 29 10:09:24 apa metabase[17168]: TRACE t557: => :mysql
Jan 29 10:09:24 apa metabase[17168]: TRACE t558: (metabase.db/db-is-setup?)
Jan 29 10:09:24 apa metabase[17168]: TRACE t558: => true
Jan 29 10:09:24 apa metabase[17168]: TRACE t559: (metabase.db/db-type)
Jan 29 10:09:24 apa metabase[17168]: TRACE t559: => :mysql
Jan 29 10:09:24 apa metabase[17168]: TRACE t561: (metabase.db/db-is-setup?)TRACE t560: (metabase.db/db-type)
Jan 29 10:09:24 apa metabase[17168]: TRACE t561: => true
Jan 29 10:09:24 apa metabase[17168]: TRACE t560: => :mysql
Jan 29 10:09:24 apa metabase[17168]: TRACE t562: (metabase.db/db-is-setup?)
Jan 29 10:09:24 apa metabase[17168]: TRACE t562: => true
Jan 29 10:09:26 apa metabase[17168]: TRACE t563: (metabase.db/db-type)
Jan 29 10:09:26 apa metabase[17168]: TRACE t563: => :mysql
Jan 29 10:09:26 apa metabase[17168]: TRACE t564: (metabase.db/db-is-setup?)
Jan 29 10:09:26 apa metabase[17168]: TRACE t564: => true
Jan 29 10:09:26 apa metabase[17168]: TRACE t565: (metabase.db/db-type)
Jan 29 10:09:26 apa metabase[17168]: TRACE t565: => :mysql
Jan 29 10:09:26 apa metabase[17168]: TRACE t566: (metabase.db/db-is-setup?)
Jan 29 10:09:26 apa metabase[17168]: TRACE t566: => true
Jan 29 10:09:26 apa metabase[17168]: TRACE t567: (metabase.server/instance)
Jan 29 10:09:26 apa metabase[17168]: TRACE t567: => #object[org.eclipse.jetty.server.Server 0x22ea31ff "Server@22ea31ff{STARTED}[9.4.32.v20200930]"]
Jan 29 10:09:26 apa metabase[17168]: 2021-01-29 10:09:26,142 DEBUG middleware.log :: GET /api/user/current 200 9.2 ms (3 DB calls) App DB connections: 1/4 Jetty threads: 4/50 (3 idle, 0 queued) (45 total active threads) Queries in flight: 0 (0 queued)
Jan 29 10:09:26 apa metabase[17168]: TRACE t568: (metabase.server/instance)
Jan 29 10:09:26 apa metabase[17168]: TRACE t568: => #object[org.eclipse.jetty.server.Server 0x22ea31ff "Server@22ea31ff{STARTED}[9.4.32.v20200930]"]
Jan 29 10:09:26 apa metabase[17168]: 2021-01-29 10:09:26,163 DEBUG middleware.log :: GET /api/session/properties 200 15.9 ms (2 DB calls) App DB connections: 0/4 Jetty threads: 3/50 (3 idle, 0 queued) (45 total active threads) Queries in flight: 0 (0 queued)
Jan 29 10:09:26 apa metabase[17168]: TRACE t569: (metabase.db/db-type)
Jan 29 10:09:26 apa metabase[17168]: TRACE t569: => :mysql
Jan 29 10:09:26 apa metabase[17168]: TRACE t570: (metabase.db/db-is-setup?)
Jan 29 10:09:26 apa metabase[17168]: TRACE t570: => true
Jan 29 10:09:26 apa metabase[17168]: TRACE t571: (metabase.server/instance)
Jan 29 10:09:26 apa metabase[17168]: TRACE t571: => #object[org.eclipse.jetty.server.Server 0x22ea31ff "Server@22ea31ff{STARTED}[9.4.32.v20200930]"]
Jan 29 10:09:26 apa metabase[17168]: 2021-01-29 10:09:26,493 DEBUG middleware.log :: GET /api/database 200 8.4 ms (3 DB calls) App DB connections: 0/4 Jetty threads: 3/50 (4 idle, 0 queued) (45 total active threads) Queries in flight: 0 (0 queued)

How can I determine what the error is, and what to do about it?

(Just by way of FYI, this didn't happen in the dev environment yesterday, everything worked fine there after getting the nginx config sorted.)

Thank you,

Hi @AccurateHamilton
Please post “Diagnostic Info” from Admin > Troubleshooting.
Check the browser developer Network-tab for any failed requests.
And you shouldn’t need to trace any errors like that - it should be fine with the regular logs.
There’s nothing in the logs indicating any problems - it’s all successful 200 requests.

The network console sorted it, it was my ad blocker catching the site name. The dev site had -dev in the name so didn’t trip it.

Thank you for your help!