In versions prior 4D v11 SQL it was possible to pass an element beyond the string length. For example:

C_TEXT($myVariable) C_TEXT($myChar) $myVariable:="Hello World" $myChar:=$myVariable[[13]]

In previous versions of 4D, the value of $myChar would be an empty string, and 4D would continue with the code execution. In version 11 this code will throw a Syntax Error 53; indice out of range. This error can be handled by checking the string length first or trapping the error with the ON ERR CALL method.