What causes "Error starting data transfer" in dbeaver/dbeaver?

Check the error dialog displayed before this exception — it shows the root cause via e.getCause()

dbeaver/dbeaver · error · DBException

Error starting data transfer

Error message

Error starting data transfer

What it means

Thrown when initializing data transfer pipes or running the transfer jobs fails with an InvocationTargetException. Before throwing, an error dialog is displayed via DBWorkbench.getPlatformUI().showError() containing the root cause (e.getCause()). The original InvocationTargetException is wrapped directly in the DBException.

Source

Thrown at plugins/org.jkiss.dbeaver.data.transfer/src/org/jkiss/dbeaver/tools/transfer/task/DTTaskHandlerTransfer.java:105

        @NotNull Locale locale,
        @NotNull Log log,
        @Nullable PrintStream logStream,
        @NotNull DBTTaskExecutionListener listener,
        DataTransferSettings settings
    ) throws DBException {
        listener.taskStarted(task);
        int indexOfLastPipeWithDisabledReferentialIntegrity = -1;
        try {
            indexOfLastPipeWithDisabledReferentialIntegrity = initializePipes(runnableContext, settings, task);
            Throwable error = runDataTransferJobs(runnableContext, task, locale, log, logStream, listener, settings);
            listener.taskFinished(task, null, error, settings);
        } catch (InvocationTargetException e) {
            DBWorkbench.getPlatformUI().showError(
                DTMessages.data_transfer_task_handler_unexpected_error_title,
                DTMessages.data_transfer_task_handler_unexpected_error_message,
                e.getCause()
            );
            throw new DBException("Error starting data transfer", e);
        } catch (InterruptedException | OperationCanceledException e) {
            //ignore
        } finally {
            restoreReferentialIntegrity(
                runnableContext,
                settings.getDataPipes().subList(0, indexOfLastPipeWithDisabledReferentialIntegrity + 1)
            );
        }
    }

    private int initializePipes(
        @NotNull DBRRunnableContext runnableContext,
        @NotNull DataTransferSettings settings,
        @Nullable DBTTask task
    ) throws InvocationTargetException, InterruptedException, DBException {
        int[] indexOfLastPipeWithDisabledReferentialIntegrity = new int[]{-1};
        DBException[] dbException = {null};
        List<DataTransferPipe> dataPipes = settings.getDataPipes();

View on GitHub (pinned to 1e5ee1042b)

Solutions

Check the error dialog displayed before this exception — it shows the root cause via e.getCause()
Verify both source and target datasources are connected and accessible before starting the transfer
Confirm driver versions are compatible with the transfer engine and the target database

Defensive patterns

Strategy: try-catch

Validate before calling

// Ensure both source and target are connected before transfer
for (DBPDataSourceContainer ds : Arrays.asList(sourceDs, targetDs)) {
    if (!ds.isConnected()) {
        ds.connect(VoidProgressMonitor.INSTANCE, true, true);
    }
}

Try / catch

try {
    handler.executeWithSettings(ctx, task, locale, log, out, listener, settings);
} catch (DBException e) {
    Throwable root = e.getCause(); // InvocationTargetException
    if (root instanceof InvocationTargetException ite) {
        root = ite.getCause();
    }
    log.error("Transfer failed", root);
}

Prevention

Verify both source and target datasource connectivity before starting a transfer
Note that an error dialog is already shown to the user before this exception propagates — avoid duplicate dialogs in your handler
Unwrap InvocationTargetException to get the true cause for logging

When it happens

Trigger: Calling DTTaskHandlerTransfer.executeWithSettings() when initializePipes() or runDataTransferJobs() throws inside a runnable. Common triggers: source or target datasource unreachable, metadata read error during pipe initialization, or the transfer job itself fails.

Common situations: Target database went offline mid-transfer. Insufficient privileges on source or target. Driver incompatibility causing metadata read failures. Network timeout during pipe setup.

Related errors

AI-assisted analysis of dbeaver/dbeaver@1e5ee1042b (2026-08-13). Data as JSON: /api/errors/6d55f0f02ac60504. Report an issue: GitHub.