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

# Common pitfalls

> Known issues in dApp Launchpad with their causes and solutions.

## MetaMask nonce error in the dev environment

**Cause:** Every time the dev environment starts, it creates a new local test chain. MetaMask caches the latest block number and the account transaction nonce. Because each `dev` run creates a fresh chain, the cached values no longer match the new chain state, causing transactions to fail.

**Solution:** Clear the MetaMask account activity cache by following the [MetaMask documentation](https://support.metamask.io/hc/en-us/articles/360015488891-How-to-clear-your-account-activity-reset-account).

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## MetaMask nonce error when using `--reset-on-change`

**Cause:** The `--reset-on-change` option resets the blockchain on every code change. After a reset, the block number and account nonce return to their initial values, but MetaMask does not clear its cache automatically.

**Solution:** Clear the MetaMask account activity cache by following the [MetaMask documentation](https://support.metamask.io/hc/en-us/articles/360015488891-How-to-clear-your-account-activity-reset-account).

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## Error: `could not coalesce error (error={ "code": -32603, "message": "Internal JSON-RPC error." })`

**Cause:** Stale wallet cache state after a chain reset or restart.

**Solution:** Clear the MetaMask account activity cache by following the [MetaMask documentation](https://support.metamask.io/hc/en-us/articles/360015488891-How-to-clear-your-account-activity-reset-account).