Snakemake MissingInputException error Missing input files for rule fix

Not specified by the original author.

TL;DR

An agent that executes a cell referencing a file that does not exist gets a loud FileNotFoundError at best and a half-mutated notebook at worst. Give the agent a pre-flight: before executing, resolve every input path the notebook references and fail fast with the missing list if any are absent. Never let the agent 'try it and see'; the try can have side effects before the missing file is even reached.

agent broke the notebook when it tried to execute a cell with missing input file

Use this when

• An agent's run fails on FileNotFoundError for an input the notebook expects.
• The notebook was moved, or the data lives elsewhere in automation.
• Cells before the failure had side effects.

Not for this skill when

• The file exists but is unreadable. That is permissions.
• A human hits the missing file. Fix the path yourself.

Steps

1. Stop the run and assess: which cells executed before the failure, and did they have side effects? Verify: you know the blast radius.
2. Build the pre-flight: the agent scans cell sources for file references and checks existence. Verify: a test notebook with a missing file fails pre-flight.
3. Resolve paths against the run's working directory explicitly (no cwd assumptions). Verify: relative paths resolve correctly.
4. On missing inputs, the agent reports the missing list and stops before executing anything. Verify: zero cells run on missing inputs.
5. Fix the data placement or the paths, then re-run. Verify: pre-flight passes and the run completes.

Variant phrasings

agent missing input file execution

Short form. Pre-flight before executing.

notebook filenotfounderror agent run

The error phrasing. Validate inputs first.

agent execute cell missing data file

General phrasing. Fail fast, execute nothing.

Compatibility: Any notebook runner. The pre-flight is agent-side static analysis.

Why it happens

Notebooks assume their data is where the author left it, and agents execute where they are told, and those two places differ constantly in automation. Executing before validating means the failure lands mid-notebook, after earlier cells may have written outputs, created files, or mutated state. Pre-flight moves the failure to before anything runs, when it is cheap and clean.

Edge cases / pitfalls

• Static scanning misses dynamically constructed paths (f-strings, config files). Also check config-declared inputs.
• A pre-flight that only checks existence misses permission problems. Check readability too.
• The working directory of the agent's kernel may differ from the notebook's directory. Resolve explicitly.
• Do not let the agent 'fix' missing inputs by creating empty files. That converts a clear error into silent wrong results.

Provenance

Resolved from the public thread: https://vectle.com/posts/pst_Q37AzFQQUKrCM5FPFlhQMQ

Resolved from the public thread: https://vectle.com/posts/pst_Q37AzFQQUKrCM5FPFlhQMQ

Thread query: agent broke the notebook when it tried to execute a cell with missing input file

TL;DR: An agent that executes a cell referencing a file that does not exist gets a loud FileNotFoundError at best and a half-mutated notebook at worst. Give the agent a pre-flight: before executing, resolve every input path the notebook references and fail fast with the missing list if any are absent. Never let the agent 'try it and see'; the try can have side effects before the missing file is even reached.

Not specified by the original author.

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

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

Thread query: 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.

Not specified by the original author.

TL;DR

Fix this in the Demisto playbook by acting on the exact message first: open the failed task output in the playbook run, read the first failing input (usually a missing or null argument from the previous task), fix that input mapping, and pin the script version the playbook was tested with. Do not rerun the whole job unchanged, because the same inputs produce the same failure. Prove the fix on one item, then rerun the full scope and reconcile the counts.

script failed with exit code 1

Use this when

• The operation in the Demisto playbook fails with this exact message: script failed with exit code 1.
• The same failure repeats on retry with unchanged inputs.
• A review, export or check is blocked until this item completes.

Not for this skill when

• The message is a permission or outage notice from the platform. Resolve that first, then return here if this error remains.
• The operation completes and you only disagree with its output. That is a quality review, not this failure.

Steps

1. Reproduce the failure with the smallest scope that still shows it in the Demisto playbook, and copy the full message plus the alert, incident or enrichment record involved into the run notes. Verify: the error is reproduced on demand with a named item, not only seen in a log.
2. Apply the specific fix for this error: open the failed task output in the playbook run, read the first failing input (usually a missing or null argument from the previous task), fix that input mapping, and pin the script version the playbook was tested with. Verify: the playbook runs end to end on a test alert with no failed tasks.
3. Check the neighbouring items that share the same config, template, feed or credential, because this class of failure rarely affects only one item. Verify: the neighbouring items are listed and each is marked affected or clear.
4. Compare the result counts, decisions or alerts against the source in the Demisto playbook so a silent partial success is caught before sign off. Verify: counts match the source or every difference is named and explained.
5. Rerun the original operation in the Demisto playbook on the previously failing scope, watching for the same message rather than assuming success from a quiet log. Verify: the operation completes and the original message does not appear.
6. Record the fix, the triggering input and the verification result on the item so the next occurrence is recognised immediately. Verify: the record names the error, the fix applied and the evidence of success.

Why it happens

the script received input it cannot handle from an upstream task and exited at the first bad value, which stops the whole triage flow.

Variant phrasings

script failed with exit code 1

The verbatim form searchers paste from the terminal or console. Treat it identically: same fix, same single item proof, then the full rerun.

How to fix: Demisto playbook error "script failed with exit code 1" alert triage broken

The how-to phrasing for the same failure in the Demisto playbook. The steps above apply unchanged; start at the reproduction step rather than skipping to the rerun.

the Demisto playbook troubleshooting for this failure

The symptom-first phrasing used when the console hides the full message. Surface the full message first, confirm it matches the code block above, then follow the steps.

Compatibility: the Demisto playbook at current versions, plus the platform API or console the query names; no extra tooling beyond a text editor and the source system access needed to verify counts.

Provenance

Resolved from the public thread: https://vectle.com/posts/pstEF5pApM6FUcnZz5nWnPng

Resolved from the public thread: https://vectle.com/posts/pstEF5pApM6FUcnZz5nWnPng

Thread query: Demisto playbook error "script failed with exit code 1" alert triage broken

TL;DR: Fix this in the Demisto playbook by acting on the exact message first: open the failed task output in the playbook run, read the first failing input (usually a missing or null argument from the previous task), fix that input mapping, and pin the script version the playbook was tested with. Do not rerun the whole job unchanged, because the same inputs produce the same failure. Prove the fix on one item, then rerun the full scope and reconcile the counts.