returns a value of -e child process not recognized.

apparently when an icons terminal value is set to true the menu automatically launches the exec= command with a -e in front of it causing the error.

the icon independently from the menu, and or double click on work as intended, but in the menu the above error occurs.

Some parts of your message seem to have gone missing.

What menu are you referring to?

panel menu

also cron jobs return a -c process error when roxterm is set as the default terminal

What panel?

I think I sooooorta understand what the problem is. I've had a similar one.

In Xfce and possibly others, when RoxTerm is set as the default terminal app in "Preferred applications", .desktop launchers that open in a terminal (e.g. htop) fail to open.

My solution was to not select RoxTerm as a launcher (which results in roxterm "%s")
But to select a custom launcher and enter roxterm -e "%s"