400 code – Invalid Signature Error (Internet Identity / ICP)

❓ What causes the 400 – Invalid signature error? Is my account or asset affected?

This error is usually caused by inconsistencies in browser cache, network conditions, system time, or identity session state.

It is not related to asset security or account safety, and it does not mean your funds are at risk.

On the Internet Computer, all authenticated requests are protected by cryptographic signatures. If the locally generated signature or delegation data becomes out of sync with what the network expects, the verification will fail and return this error.

For more technical details, please refer to the official documentation: Verifying Signatures on the Internet Computer

✅ Recommended Solutions

Please try the following steps in order. In most cases, one of these will resolve the issue:

• Reconnect your wallet / re-login with Internet Identity. Log out completely and sign in again to refresh your identity session and delegation.

• Clear your browser cache and site data. Especially IndexedDB, LocalStorage, and cookies related to Internet Identity or the dApp.

• Disable VPNs, proxies, or network acceleration tools. These tools may interfere with signature validation or request routing.

• Check and sync your system time. Ensure your device time is accurate and set to automatic synchronization, as signature validation depends on time-based validity windows.

• Try using a private / incognito browser window. This helps rule out issues caused by cached identity data or browser extensions. This workaround has been recommended by developers on the official DFINITY forum