---
title: Troubleshooting C / C++ SDK Issues
description: Learn how to troubleshoot common issues with the RUM C++ SDK.
breadcrumbs: >-
  Docs > RUM & Session Replay > Application Monitoring > C / C++ Monitoring >
  Troubleshooting C / C++ SDK Issues
---

> For the complete documentation index, see [llms.txt](https://docs.datadoghq.com/llms.txt).

# Troubleshooting C / C++ SDK Issues

{% callout %}
# Important note for users on the following Datadog sites: app.ddog-gov.com, us2.ddog-gov.com

{% alert level="danger" %}
This product is not supported for your selected [Datadog site](https://docs.datadoghq.com/getting_started/site.md). ({% placeholder "user-datadog-site-name" /%}).
{% /alert %}

{% /callout %}

## Overview{% #overview %}

If you experience unexpected behavior with the Datadog C++ SDK, use this guide to resolve issues. If you continue to have trouble, contact [Datadog Support](https://docs.datadoghq.com/help) for further assistance.

## Enable diagnostic logging{% #enable-diagnostic-logging %}

The SDK outputs `Warning` and `Error` messages to stderr by default. To see more verbose output during development, lower the diagnostic threshold on your `CoreConfig` before creating the core:

```
datadog::CoreConfig config("<client_token>", "<service_name>", "<environment>");
config.SetDiagnosticThreshold(datadog::DiagnosticLevel::Debug);

auto core = datadog::Core::Create(config, datadog::TrackingConsent::Granted);
```

You should see output similar to the following when data is successfully uploaded:

```
[DATADOG STATUS] Upload cycle finished with all uploads successful
```

**Recommendation:** Remove the `SetDiagnosticThreshold` call in production builds to revert to the default (`Warning`) and avoid unnecessary log volume.

To route diagnostic output somewhere other than stderr, supply a custom handler. The `msg.text` pointer is only valid for the duration of the call, so copy the string if you need to store it:

```
config.SetDiagnosticHandler([](const datadog::DiagnosticMessage& msg) {
    my_logger.write(msg.text);
});
```

Pass `nullptr` to `SetDiagnosticHandler` to suppress all diagnostic output entirely.

## Runtime Issues{% #runtime-issues %}

**No data appears in Datadog**

If your application runs but data does not appear in the Datadog UI, check the following:

1. **Tracking consent**: Confirm that tracking consent is set to `Granted`. If the core was initialized with `Pending` or `NotGranted`, no data is uploaded.
1. **`Start()` was called**: The SDK does not collect or upload data until `core->Start()` is called after all features are registered.
1. **Active view**: RUM errors, resources, and actions are attached to the active view. If no view has been started with `StartView()`, those events may be dropped. Start a view before recording other events.
1. **Network connectivity**: The SDK requires outbound HTTPS access to Datadog intake endpoints on port 443. Verify that your network allows these connections.
1. **Diagnostic output**: Lower the diagnostic threshold (see above) and look for messages indicating upload failures or configuration errors.

**Storage directory is not writable**

If diagnostic output shows storage errors, verify that the storage directory exists and is writable by the application process. The SDK uses the directory set with `SetApplicationStoragePath()`, or the current working directory by default.

**Crash reports are not appearing after a crash**

Crash reports are uploaded on the **next application launch** after the crash, not immediately (since the process is terminated at crash time). After triggering a test crash, relaunch the application and wait for the upload to complete.

If reports still do not appear:

- Confirm that `CrashReporting::Register()` is called after creating the core but before `core->Start()`.
- Verify that the application has write access to its storage directory.
- Check that the `crashpad_handler` executable is present in the same directory as your application binary (if using Crashpad mode). Use `datadog_enable(your_target)` in CMake to copy it automatically.

## Further reading{% #further-reading %}

- [Source code for dd-sdk-cpp](https://github.com/DataDog/dd-sdk-cpp)
- [Explore Real User Monitoring](https://docs.datadoghq.com/real_user_monitoring.md)