Error Code Reference

Understand, diagnose, and resolve errors that occur during workflow execution.

EW-FLOW uses numeric error codes organized by category. These codes appear on the Logs page and in Session Details when something goes wrong. Each error code belongs to a category identified by its numeric range, making it easy to determine which subsystem produced the error.

How error codes work

Field	Description
Code	Numeric identifier — the unique error ID (e.g., 4001)
Name	Machine-readable short name (e.g., ModuleException)
Category	The subsystem that produced the error (e.g., Module, Token, Flow)
Severity	Indicates impact level
Description	Human-readable explanation of what went wrong
Resolution	Steps the user can take to resolve the issue

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Generic (0xxx)

General errors that do not belong to a specific subsystem.

Code	Name	Severity	Description	Resolution
0000	Generic	—	An unclassified error occurred.	Check the error message for details. If the issue persists, contact support.

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Other (1xxx)

Errors related to project and channel resolution.

Code	Name	Severity	Description	Resolution
1001	ProjectNotFound	—	The requested project could not be found.	Verify the Process exists and is deployed to the correct Environment.
1002	ChannelNotFound	—	The communication channel could not be resolved.	Check that the channel is properly configured in the Environment settings.

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Flow (2xxx)

Errors that occur during the workflow execution flow — token movement, node traversal, and loop detection.

Code	Name	Severity	Description	Resolution
2001	OnGetNextNode	—	Failed to determine the next node in the Process.	Verify that all nodes have valid outgoing Sequence Flows in the editor.
2002	LoopLimit	—	The workflow exceeded the maximum allowed loop iterations.	Review your Process for unintended infinite loops or increase the loop limit if intentional.
2003	SessionAlreadyEnded	—	An operation was attempted on a Session that has already stopped.	No action needed — the Session has completed. Start a new Session if required.
2004	RunIgnoredAwaitingTaskCallback	—	Execution was skipped because the workflow is waiting for an external task callback.	Ensure the external system sends the expected callback to the Environment URL.
2005	ReportNotFound	—	The requested execution report could not be found.	Verify the Session ID is correct. The report may have expired based on your Service Plan retention.

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Task (3xxx)

Errors related to Task resolution and data within BPMN nodes.

Code	Name	Severity	Description	Resolution
3001	TaskNoData	—	A Task node was reached but contains no configured data.	Open the Process Editor and configure the Task's properties.
3002	TaskNotImplemented	—	The Task type exists but has no execution handler.	Ensure the required Module is installed from the Marketplace.
3003	TaskNotFound	—	The referenced Task could not be found in the Process definition.	Re-deploy the Process. If the issue persists, verify the BPMN file integrity.
3004	TasksWithSameId	—	Two or more Tasks share the same identifier.	Open the Process Editor and ensure each Task has a unique ID. This usually requires recreating duplicate nodes.
3005	TaskInvalidData	—	The Task's configured data is malformed or invalid.	Open the Task in the Process Editor and verify all required properties are set correctly.

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Module (4xxx)

Errors originating from Module execution — the most common category during runtime.

Code	Name	Severity	Description	Resolution
4001	ModuleException	—	An unhandled exception occurred inside a Module during Task execution.	Check the error message for details. Verify the Module's Environment configuration.
4002	MissingServiceId	—	The Module could not resolve the service identifier for the Task.	Re-deploy the Process. If the issue persists, reinstall the Module from the Marketplace.
4003	ServiceConfigurationError	—	The Module's Environment configuration is invalid or incomplete.	Go to Environments and verify all required configuration fields for this Module are filled in.
4004	ModuleMissingService	—	The execution service for this Task is not registered.	Ensure the Module is installed for this Process in the Marketplace.
4005	ModuleMissingNodeData	—	The Task node has no data attached to it.	Open the Process Editor and configure the Task's properties.
4006	ModuleGenericException	—	A generic error occurred within a Module.	Check the error message for specifics. Review Module configuration and Task properties.
4007	ModuleMissingServiceInterface	—	The Module is missing a required service interface registration.	This is typically an internal issue. Contact support if the Module was recently updated.
4008	ModuleMissingConfiguration	—	The Module requires Environment configuration but none was found.	Go to Environments, select the Environment, and fill in the Module's configuration. Look for the "missing" tag.
4009	ModuleInputEmpty	—	A Module Task expected input but received an empty value.	Verify that previous Tasks in the workflow are setting the expected session variable.
4010	ModuleInputNotInSession	—	The variable referenced by the Task does not exist in the Session data.	Check that the variable name in the Task matches what was set by a previous Task. Variable names are case-sensitive.
4011	ModuleInvalidInput	—	The input provided to the Module Task is in an unexpected format.	Verify the data type and format of the session variable being passed to the Task.
4012	ModuleInvalidData	—	The Module Task's internal data is corrupted or unparseable.	Re-configure the Task in the Process Editor and re-deploy.
4013	ModuleLog	—	An informational log entry produced by a Module (not necessarily an error).	Review the message — this may be diagnostic output rather than a failure.
4014	ModuleNotFound	—	The referenced Module is not installed in this Process.	Install the required Module from the Marketplace for this Process.
4015	ModuleProcessorNotFound	—	The Module's Task processor could not be located.	Re-deploy the Process. If the issue persists, contact support.
4020	WebhookSignatureInvalid	—	An incoming webhook request failed its signature check and was rejected.	Verify the shared secret in the Module's Environment configuration matches the secret configured on the sending system, and that the request body is sent unmodified.
4021	OtpNotApproved	—	A one-time passcode (OTP) verification returned a non-approved status — the code was wrong, expired, or the maximum attempts were exceeded.	Ask the user to re-enter the code or request a new one. Route the verification Task's error output to a retry branch in your Process.

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Token (5xxx)

Errors related to the execution Token — the pointer that moves through your Process.

Code	Name	Severity	Description	Resolution
5001	TokenNotFound	—	The execution Token could not be found.	The Session may have expired or been corrupted. Start a new Session.
5002	TokenAlreadyStopped	—	An operation was attempted on a Token that has already stopped.	No action needed — the Token completed its path. Start a new Session if required.
5003	ErrorCreatingToken	—	Failed to create a new execution Token for the Session.	Re-deploy the Process and try again. If the issue persists, contact support.
5004	TokenNotFoundInSession	—	The Token was expected in the Session but could not be located.	The Session may be in an inconsistent state. Start a new Session.
5005	RootExecutionInvalid	—	A child workflow was started with a parent Session reference that does not exist or belongs to a different Workspace.	Ensure the handler workflow and the Session that starts it are deployed in Environments of the same Workspace, and that the parent Session still exists.

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Process (6xxx)

Errors related to Process definition, deserialization, and deployment validation.

Code	Name	Severity	Description	Resolution
6001	ProcessIsNull	—	The Process definition is null or missing.	Re-deploy the Process from the editor.
6002	ProcessDeserializationError	—	The Process BPMN data could not be parsed.	The Process file may be corrupted. Try opening a previous version from Process History.
6003	ProcessNotFound	—	The referenced Process does not exist.	Verify the Process exists in the current Workspace. It may have been deleted.
6004	ProcessDuplicatedPool	—	Two or more Pools in the Process share the same identifier.	Open the Process Editor and ensure each Pool has a unique name/ID.
6005	TaskDuplicated	—	A Task ID appears more than once in the Process definition.	Open the Process Editor and remove or recreate the duplicate Task.

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Session (7xxx)

Errors related to Session lifecycle — creation, updates, and lookups.

Code	Name	Severity	Description	Resolution
7001	SessionNotFound	—	The requested Session does not exist.	Verify the Session ID. It may have been purged based on your Service Plan retention.
7002	SessionUpdateError	—	Failed to update the Session's state.	Retry the operation. If the issue persists, contact support.
7003	SessionNotCreated	—	A new Session could not be created.	Check that the Process is deployed and the Environment is active.

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Environment (8xxx)

Errors related to Environment resolution, configuration, and deployment targets.

Code	Name	Severity	Description	Resolution
8001	EnvironmentNotFound	—	The referenced Environment does not exist.	Verify the Environment exists and has not been deleted.
8002	EnvironmentNotActive	—	The Environment exists but is currently disabled.	Go to Environments and set the Environment status to active.
8003	EnvironmentConfigurationNotFound	—	Module configuration for the Environment is missing.	Go to Environments and fill in the missing Module configuration (look for the "missing" tag).
8004	EnvironmentNoVersionFound	—	No Process version has been deployed to this Environment.	Deploy a Process version to this Environment from the Process Editor.
8005	ProcessVersionNotFoundInEnvironment	—	The specific Process version could not be found in this Environment.	Re-deploy the Process. The version may have been overwritten.
8006	InvalidShortUrl	—	The short URL used to reach the Environment is invalid.	Verify the URL matches the one shown on the Environments page.
8007	RedisSaveFailure	—	Failed to save session state to the cache.	This is usually a transient issue. Retry the operation. If persistent, contact support.
8008	ProcessVersionNotFound	—	The Process version reference could not be resolved.	Re-deploy the Process from the editor.
8009	NoTransport	—	No communication transport is configured for the Environment.	Ensure the Environment has a valid channel/transport configured.
8010	TaskNoPaths	—	A Task in the Process has no outgoing Sequence Flows.	Open the Process Editor and connect the Task to the next element.
8011	NoPathsInProcess	—	The Process has no Sequence Flows defined at all.	Open the Process Editor and connect your elements with Sequence Flows.
8012	StartTaskNotFound	—	The Process does not contain a Start Event.	Open the Process Editor and add a Start Event node to your Process.
8013	TasksHasNoType	—	A Task in the Process has no type defined.	Open the Process Editor and ensure the Task has a valid type configured (e.g., a Module assignment).
8014	NoOutgoingConnections	—	A Task has no outgoing connections and is not an End Event.	Open the Process Editor and either connect the Task to the next element or replace it with an End Event.
8015	InvalidExecutionState	—	The execution state is corrupted (e.g., TaskId became null mid-execution).	This indicates an internal consistency error. Re-deploy the Process and retry. If the issue persists, contact support.
8016	ConnectionNotFound	—	A Task references an outgoing connection ID that does not exist in the Process.	The Process definition may be corrupted. Re-deploy from the Process Editor or revert to a previous version from Process History.
8017	TargetTaskNotFound	—	A Sequence Flow references a target Task that does not exist in the Process.	The Process definition may be corrupted. Re-deploy from the Process Editor or revert to a previous version from Process History.