An error message occurs when building 'Program$2\text{'}.$ Briefly detail why this error message occurs.

$($marks $3)($ii$)$ Write a corrected version of 'Program$2\text{'}$ in your answer booklet.

$($marks $2\mathrm{.}5)$ Based upon your corrected version of 'Program$2\text{'},$ what is the value of the variable 'out' after the $2$ nd execution of 'Program$2\text{'}?$

$($marks $3)($d$)$ What is the value of the variable DISPLAY, after the execution of the ST code$-$snippet below, when Ctrl$-$Il$?$