The issue you're facing with editing or creating Data Collection Rules (DCR) in Azure Monitor, where errors like "Preflight validation failed" and "Stream invalid" are encountered, is likely due to a problem with the user interface (UI) in the Azure portal. This was identified during troubleshooting where it was found that while the changes couldn't be made via the portal, they could be successfully executed using the API.
To resolve this issue, you can use the API to make the necessary changes to your Data Collection Rules. You can find the relevant API documentation and try making the changes via the API endpoint provided in the documentation.
For detailed steps on using the API for creating and managing Data Collection Rules, refer to the official Azure documentation: Create or Update Data Collection Rule (DCR) - Azure Monitor.
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