The XAML rendering extension, used by the WPF Report Viewer, by default checks for invalid characters while writing the XAML page contents. When the data that will be rendered on the page contains invalid Unicode characters, an exception is thrown and the report is not rendered.

The current solution is to introduce a UserFunction that parses  the string contents and strips the invalid characters, but implementing and maintaining this approach requires more efforts from the developer.

An option in the XAML Device Information Settings that disables the check for invalid characters, would work in most scenarios without having to write a dedicated UserFunction. By default this option will preserve the current behavior, i.e. the characters checking will be performed, but the developers will have the ability to disable it on their own discretion.