# Source: https://upstash.com/docs/redis/sdks/ts/troubleshooting.md

> ## Documentation Index
> Fetch the complete documentation index at: https://upstash.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Troubleshooting

## ReferenceError: fetch is not defined

#### Problem

If you are running on nodejs v17 and earlier, fetch will not be natively
supported. Platforms like Vercel, Netlify, Deno, Fastly etc. provide a polyfill
for you. But if you are running on bare node, you need to add a polyfill.

#### Solution

```bash  theme={"system"}
npm i isomorphic-fetch
```

```ts  theme={"system"}
import { Redis } from "@upstash/redis";
import "isomorphic-fetch";

const redis = new Redis({
  /*...*/
});
```

## Hashed Response

The response from a server is not what you expect but looks like a hash?

```ts  theme={"system"}
await redis.set("key", "value");
const data = await redis.get("key");
console.log(data);

// dmFsdWU=
```

#### Problem

By default `@upstash/redis` will request responses from the server to be base64
encoded. This is to prevent issues with some edge cases when storing data where
the http response fails to be deserialized using `res.json()`

This solves the problem for almost all edge cases, but it can cause new issues.

#### Solution

You can disable this behavior by setting `responseEncoding` to `false` in the
options.

```ts  theme={"system"}
const redis = new Redis({
  // ...
  responseEncoding: false,
});
```

This should no longer be necessary, but if you are still experiencing issues
with this, please let us know:

* [Discord](https://discord.gg/w9SenAtbme)
* [X](https://x.com/upstash)
* [GitHub](https://github.com/upstash/upstash-redis/issues/new)

## Large numbers are returned as string

You are trying to load a large number and it is returned as a string instead.

```ts  theme={"system"}
await redis.set("key", "101600000000150081467");
const res = await redis("get");

// "101600000000150081467"
```

#### Problem

Javascript can not handle numbers larger than `2^53 -1` safely and would return
wrong results when trying to deserialize them. In these cases the default
deserializer will return them as string instead. This might cause a mismatch
with your custom types.

#### Solution

Please be aware that this is a limitation of javascript and take special care
when handling large numbers.