/ was not found on this server.Hello Peter,
As Nicolas mentioned, this error usually related to app.yaml file configuration issue. However, I would recommend to check any other configuration file if you have, such as dispatch.yaml [1]
By looking at the errors, it seems like request reached to the application. If this is the case, you can investigate the logs from Stackdriver Logging. I would say check the Stackdriver Logging to find any request with ‘404’ status in your particular App Engine version which might help you to figure out the issue.
[1] https://cloud.google.com/appengine/docs/flexible/nodejs/reference/dispatch-yaml
Hi Peter,
Thanks for your replies,
This discussion group is oriented more towards general opinions, trends, and issues of general nature touching App Engine.
For coding and programming architecture, you may be better served in dedicated forums such as Stack Overflow, where experienced programmers are within reach and ready to help.