Hi, Himanshi -
You have given very little information to help us help you. Can you please provide:
1. The external function declaration in the PowerBuilder app.
2. A snippet of code where the external function is called, including the declarations of any variables used as arguments.
3. If you are NOT calling a Windows API function, then please also provide any documentation regarding the calling argument(s) of the DLL function.
Does the external function call work when then app is executed from the IDE (as 32-bit)?
Does the compiled 64-bit PB app have a 64-bit version of the external DLL available? The bitness of the app and the DLL must match.
Best regards, John