Unable to provide accurate object property suggestions.

I have defined an activity in C# and it includes an output:

[ActivityOutput()]
public Exception Exception { get; set; }

This output type cannot be used with JS editing hints in the designer; it always displays "any" as "MyActivityObj.Exception: any"
How can I fix this? Is this issue caused by the simultaneous existence of the "Exception" type definition in JS and C#?

Start by reproducing the C# ActivityOutput using Exception and inspect how the designer generates JavaScript editing hints for MyActivityObj.Exception. Compare the handling of the Exception type definitions in C# and JavaScript, then verify that the designer reports the accurate property type instead of any.

Written by the indexing model from the issue text.