I'm developing visual studio using crystal report for visualstudio edition.
I downloaded development & runtime for latest version from this site.
Also, I'm developing with visual studio 2019, C#, on WPF platform.
But when I import the controller and run the app,
the reporting viewer open and shows a popup saying that
"object reference not set to an instance of an object"
Because it shows pop up, I can't dig into the problem using the debugging mode.
even if the .rpt file consists of only static text, ( so there's no datasource ) it says the same problem.
but when I comment below line,
the error pop-up doesn't show up, but it's an only empty viewer with 0 page.
any idea is really appreciated.