File generation issues while using $ZF(-100 asynchronously

Hello Community,

We use $ZF(-1 synchronous call to generate the pdf files. Now I want to change to asynchronously. So, I use $ZF(-100 with "/ASYNC" function. I use "/ASYNC" directly write $ZF(-100,"/ASYNC","notepad.exe") in windows/linux it throws the <NOTOPEN> error, However If I use $ZF(-100,"/ASYNC /SHELL","notepad.exe") it opens the notepad without issues.

However, I execute the below in Linux system the file is not generated properly. But  $ZF(-2,"/ASYNC /SHELL", " /fop/fop -r -fo ""/grp1/tempXSL-FO.TT.12.xml"" -pdf ""/grp1/tempXSL-FO.TT.12.pdf"" 1>/dev/null 2>""/grp1/tempXSL-FO.TT.12.err"" ") this works

write $ZF(-100,"/ASYNC /SHELL", " /fop/fop -r -fo ""/grp1/tempXSL-FO.TT.12.xml"" -pdf ""/grp1/tempXSL-FO.TT.12.pdf"" 1>/dev/null 2>""/grp1/tempXSL-FO.TT.12.err"" ")

Thanks!