React TypeError: "This is undefined" is an error that occurs when trying to access a property or call a function on an undefined value in a React application. This error typically happens when there is a mistake in the code, such as not properly initializing a variable or not binding a function correctly.

To fix this error, you need to identify the specific line of code where the error is occurring and then check for any potential issues. Here are some common scenarios that can cause this error:

1. Undefined variable: Make sure that all variables are properly declared and initialized before using them. Check if the variable is being assigned a value correctly or if it is being accessed before it is defined.
2. Incorrect function binding: If you are passing a function as a prop or using it as an event handler, ensure that the function is properly bound to the correct context. You can use the bind method or arrow functions to ensure the correct binding.
3. Asynchronous operations: If the error occurs within an asynchronous operation, such as a callback or a promise, make sure to handle any potential errors and check if the value being accessed is defined before using it.

It's important to note that the specific cause of the error may vary depending on the context and code structure. Therefore, it's recommended to carefully review the code and debug the issue to find the exact cause.

As for the recommended Tencent Cloud products related to React development, you can consider using the following:

1. Tencent Cloud Serverless Cloud Function (SCF): SCF allows you to run your code without provisioning or managing servers. It can be used to deploy serverless functions that can be triggered by events, such as HTTP requests. You can find more information about SCF here.
2. Tencent Cloud CloudBase: CloudBase provides a serverless application platform that supports various front-end frameworks, including React. It offers features like automatic scaling, CI/CD integration, and built-in databases. You can learn more about CloudBase here.

Remember to adapt the above recommendations to your specific requirements and consult the Tencent Cloud documentation for detailed usage instructions.