> ## Documentation Index > Fetch the complete documentation index at: https://interceptor-docs.requestly.com/llms.txt > Use this file to discover all available pages before exploring further. # Error on saving rule > If you encounter an error while saving a rule in Requestly Interceptor, follow the steps below to identify and resolve the issue:

## 1. Check Console for Error Details Open the **Developer Console** in your browser (Right-click → Inspect → Console tab).\ You will find an error message logged along with the **Rule ID** that caused the issue. This information is essential for debugging or sharing with the support team if needed. ## 2. Common Errors and Resolutions ### a. Regex Size Limit Exceeded If the error message indicates that the regex exceeds the supported size limit, please refer to this issue for known limitations and potential workarounds:\ [Regex Size Limit Issue #1690](https://github.com/requestly/requestly/issues/1690) ### b. Invalid Regex / Unsupported Lookaheads If the error message mentions *"Invalid regex"* or unsupported syntax such as **lookaheads**, it means the pattern is not compatible with the regex engine we use. Requestly Interceptor uses **RE2-compatible regular expressions**, as required by **Chrome's Manifest V3** security model.\ This is a technical limitation imposed by Chrome, and not something we can bypass. For reference on RE2-compatible syntax, you can visit:\ [RE2 Syntax Documentation](https://github.com/google/re2/wiki/Syntax) ## 3. Still Facing Issues? If your error does not fall under the above categories, or you're unsure how to proceed, please: * Note the **error message** from the console. * Contact our support team or file an issue with details on [GitHub](https://github.com/requestly/requestly/issues).