runtime.mongo_auth

MongoDB rejected the login or password

A mevcore app hosting error at the “start / health check” stage.

What it means

The user or password in the MongoDB connection string is wrong.

The build passed, but the app did not start or did not answer the health check.

Typical causes

The app does not listen on 0.0.0.0 and the port from the PORT variable
An environment variable is missing, or the database or Redis is not connected
The start command is wrong or the process exits right away

How to fix it on mevcore

Check them in the variable on the «Environment» tab; encode special characters of the password (@ → %40) and add authSource=admin if the user was created in the admin database.

1 Open the app in the mevcore panel: the Problems card on the overview shows this error and the log line it was found in.
It is fixed on the “Environment” tab of the app.
2 After the fix, deploy again. If it fails again, the log ends with [mevcore] lines naming the new error code.
3 The "Ask AI" button next to the error prepares a request for ChatGPT or Claude: the error code, the end of the log without secrets and the app settings.

For an AI assistant

The same in English: paste it together with the log into the AI chat.

mevcore error code: runtime.mongo_auth
phase: start / health check
diagnosis: MongoDB rejected the login or password
platform hint: The user or password in the MongoDB connection string is wrong. Check them in the variable on the «Environment» tab; encode special characters of the password (@ → %40) and add authSource=admin if the user was created in the admin database.
platform docs: https://mevcore.com/llms-full.txt

Can't fix it?

Message support with the error code: we will tell you what to change in the project or settings.

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