Still,

Declare DLL caused an exception

:-(

>I don't understand why you need the FindWindow call. Try this simplified version. It works fine on my machine.
>If it works, you need to change the hardcoded URL.
>
>

>tcUrl = IIF(type("tcUrl")="C",tcUrl,"https://www.vfphelp.com/vfp9/index.htm")
>tcAction = IIF(type("tcAction")="C",tcAction,"Open")
>IF type("Application.StartMode") = "N" AND !inlist(Application.StartMode,2,3,5)
>  *  UI only when not being called from a COM server
>  WAIT WINDOW "Loading " + tcURL + " ..." NOWAIT
>ENDIF
>DECLARE INTEGER ShellExecute IN SHELL32.dll ;
>     INTEGER nWinHandle, ;
>     STRING cOperation, ;
>     STRING cFileName, ;
>     STRING cParameters, ;
>     STRING cDirectory, ;
>     INTEGER nShowWindow
>RETURN ShellExecute(0,tcAction,tcUrl,"",'',1)

>
>>Hi Tore
>>
>>this line
>>
>>RETURN ShellExecute(FindWindow(0,_Screen.Caption),tcAction,tcUrl,"",SYS(2023),1)
>>
>>>>Hello all,
>>>>
>>>>I will have a button on form. When the user clicks that button I want to launch where the user can make it's payment.
>>>>
>>>>My app is on WIndows Server 2016.
>>>>
>>>>So far someone gave me this code
>>>>
>>>>

>>>>lParameters tcURL, tcAction
>>>>tcUrl = IIF(type("tcUrl")="C",tcUrl,"https://square.link/u/HereCodeForThePersonWhowillBePaid")
>>>>tcAction = IIF(type("tcAction")="C",tcAction,"Open")
>>>>IF type("Application.StartMode") = "N" AND !inlist(Application.StartMode,2,3,5)
>>>>  *  UI only when not being called from a COM server
>>>>  WAIT WINDOW "Loading " + tcURL + " ..." NOWAIT
>>>>ENDIF
>>>>DECLARE INTEGER ShellExecute IN SHELL32.dll ;
>>>>     INTEGER nWinHandle, ;
>>>>     STRING cOperation, ;
>>>>     STRING cFileName, ;
>>>>     STRING cParameters, ;
>>>>     STRING cDirectory, ;
>>>>     INTEGER nShowWindow
>>>>DECLARE INTEGER FindWindow IN WIN32API ;
>>>>     STRING cNull, ;
>>>>     STRING cWinName
>>>>RETURN ShellExecute(FindWindow(0,_Screen.Caption),tcAction,tcUrl,"",SYS(2023),1)
>>>>

>>>>
>>>>First time I executed that code I received this : Declare DLL caused an exception
>>>>Second time I executed my VFP session froze.
>>>>
>>>>Suggestion?
>>>>
>>>>Regards
>>>
>>>Which line gave the error?