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title: Troubleshooting Regular Expression Compatibility Issues
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product: Omni Gateway
version: 1.9
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# Troubleshooting Regular Expression Compatibility Issues

> For the full documentation index, see: https://docs.mulesoft.com/llms.txt

Troubleshoot compatibility issues that occur when using regular expressions:

- [Negative Lookaheads](#troubleshoot-negative-lookaheads)

## Negative Lookaheads

Flex Gateway conforms to
[Google RE2 regular expression syntax](https://github.com/google/re2/wiki/Syntax), which does not
support negative lookaheads.

## See Also

- [Known Issues](https://help.salesforce.com/s/issues)