Exim Configuration Advanced Editor displays warning despite valid redirect_router entries

Symptoms

When attempting to save custom routers in "WHM / Service Configuration / Exim Configuration Manager / Advanced Editor" a warning similar to the one below will be displayed even if the router information is valid.

Description

The Advanced Editor in "WHM / Service Configuration / Exim Configuration Manager" is displaying a warning when attempting to save the configuration. Regardless of this warning, you can still save the configuration after accepting the warning.

We've opened an internal case for our development team to investigate this further. For reference, the case number is CPANEL-50075. Follow this article to receive an email notification when a solution is published in the product. 

Workaround

Ignore the warning.