> ## Documentation Index
> Fetch the complete documentation index at: https://docs.mantrixflow.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Troubleshooting

> Resolve common MantrixFlow connection, discovery, preview, validation, delivery, and billing problems.

Start with the failed action and its message. Never paste passwords, access tokens, or connection strings into support messages.

## Connection test failed

Verify the hostname, port, database, username, password, SSL mode, and network access. For a private database, follow [Private database access](/connections/private-database-access).

## Schema discovery returned no streams

Confirm that the source user can read the expected schema or API resources. For Asana, verify the PAT owner can access the selected workspace and projects. For HubSpot and Stripe, verify the required token permissions in the connector reference.

For Zendesk, verify that the connection was authorized against the correct core
subdomain and that the approving user can read the selected Support resource.
Reconnect the account if OAuth access was revoked or expired.

## Data Preview is empty

Confirm that the selected stream contains records and that the current connection can read them. Refresh discovery before retrying when the source schema changed.

## SQL validation failed

Check the source reference, selected columns, and SQL syntax. The model output columns must match the pre-created destination table. See [SQL Layer](/pipelines/dbt-layer).

## Pipeline Run failed before delivery

Common causes include:

* the source table or stream is no longer available;
* source or destination permissions changed;
* the destination table does not exist;
* the SQL output contains a column missing from the destination table;
* Incremental sync is missing a valid replication key; or
* the workspace reached a plan limit.

Open **Runs**, select the failed pipeline run, and use the named phase and error message to identify the next action.

## Incremental sync repeated records

Check that the replication key is stable and increases as records change. The destination should have a primary key for merge-style Upsert behavior. Review [Incremental sync](/sync-reference/incremental-sync) and [Sync state](/sync-reference/sync-state).

## Billing or checkout did not update

Confirm that the hosted checkout completed, then refresh **Settings → Billing**. For an unresolved payment or plan issue, contact [support@mantrixflow.com](mailto:support@mantrixflow.com) with the workspace name and billing email.