Tableau Prep flow failed before dashboard refresh: input file not found error

TL;DR

Restore the input at the path the flow expects, or edit the input step to the new location, then run the flow and the dependent refresh in order. Prep flows store absolute or network paths for file inputs, so a moved, renamed or archived input stops the flow at its first step and the downstream dashboard simply never updates.

Tableau Prep flow failed before dashboard refresh: input file not found error

Use this when

• A Prep flow fails immediately and the run history names an input file path.
• The downstream extract or dashboard stopped updating at the same time as the flow failure.
• The input file was moved, renamed, or archived by an upstream team or a cleanup process.

Not for this skill when

• The flow completes but output values are wrong. Debug the flow logic steps instead.
• The flow fails at a database input step with a login error. Fix that connection separately.

Steps

1. Open the failed flow run history and record the exact path and file name the input step tried to read. Verify: the error names one input step and one full path
2. Check that path from the server perspective, confirming the Prep service account can see the folder and the file. Verify: the file exists at that path with a recent modified time, or is confirmed missing
3. If the file moved, either restore a copy to the expected path or edit the flow input step to the new location and republish the flow. Verify: the input step preview loads rows in Prep Builder
4. Run the flow on demand and watch it pass the input step into the cleaning steps. Verify: the flow run completes and writes its output with a new timestamp
5. Run the dependent extract refresh or dashboard data update that the flow feeds. Verify: the dashboard shows the new data window after the refresh
6. Set a monitor or a simple file presence check ahead of the scheduled flow so a missing input is caught before the run window. Verify: a test removal of a copy triggers the alert path you configured

Why it happens

File inputs are the fragile edge of Prep flows because they depend on shared storage discipline outside Tableau. The flow file itself cannot carry the input data, so path stability and service account access decide whether the run starts at all. Teams that publish inputs to a managed location with a retention rule, rather than a personal folder, see this failure far less often.

Tableau Prep reads inputs at run time from the locations saved in the flow. On a server, those paths are resolved by the Prep Conductor service account, not by the flow author machine. A file that exists for the author can still be missing for the server because of a different drive mapping, a moved share, or a cleanup job that archived the file. The flow run history names the input step and the path it tried.

Field notes for Tableau specifically. The server and cloud admin views are the reliable evidence source, background task history for refresh and flow runs, and the data source details page for connection and permission state. Desktop behaviour is a weak proxy for server behaviour because the server runs as a different account, from a different network position, with different file access. Whenever a failure differs between Desktop and server, believe the server view and reproduce there, ideally with the same content and the same schedule the viewers depend on.

For Tableau estates, a simple content register pays for itself quickly, one row per production data source naming its owner, its refresh cadence, its upstream system, and the dashboards that depend on it. Most dashboard incidents are dependency incidents, and the register turns the first question of every investigation, what feeds this and who owns it, into a lookup. Review the register whenever a source is renamed, moved, or republished, because those three operations cause the majority of Tableau dashboard breakage.

Variants and edge cases

Tableau Prep input file not found flow failed fix

The direct phrasing from the flow run error.

Tableau Prep Conductor cannot find input file path

The server-account variant for scheduled flows.

dashboard stale Prep flow missing input file restore

The downstream-symptom phrasing starting from the stale dashboard.

Provenance

Resolved from the public thread: https://vectle.com/posts/pstEeSR0pc3Z0lyv3DOVRigw