macOS WebView!? crashing on window minimize or hide

[artbeat.easy]

my Window have WebView
and i try minimize window and handle this error:

<Error>: kCGErrorIllegalArgument: _CGSFindSharedWindow: WID -1
<Error>: kCGErrorFailure: Set a breakpoint @ CGErrorBreakpoint() to catch errors as they are logged.
<Error>: kCGErrorIllegalArgument: CGSDeviceCreate: Invalid window
<Error>: Failed to create window context device
<Error>: CGWindowContextCreate: failed to create context delegate.
_initWithWindowNumber: error creating graphics ctxt object for ctxt:0x15de7, window:0xffffffff

in my WebView i loading swf document

 

[kainjow]

How are you creating your WebView? Do you have any code samples?