MULTI can insert special checks into the program to watch for and report a broad variety of run-time errors. By pinpointing the source line at which the error first occurs, error checking saves many hours of time hunting down very intricate problems. Error checking saves a lot of time finding simpler bugs as well, and that time adds up quickly over the course of a programming project. MULTI can check for several errors including:

	Allocation - Reading or writing unallocated memory.
	Free - Freeing unallocated memory.
	Memory Leak - Detecting dynamically allocated memory blocks not referenced by any program pointer.
	Array Bounds - Accessing an element beyond the declared bounds of an array.
	Assignment Bounds - Storing a value into a variable or bit field too small to hold it.
	NULL Dereference - Using a null pointer to access memory.
	Switch/Case Statement - Having a parameter to a switch/case statement which does not match any of the case labels.
	Divide by Zero - Dividing by zero.
	Unused Variables -Having a local variable which is never used, or which is read before being initialized.
	Watchpoint - Accessing a specified memory address.
	Return - Exiting from a non-void function without returning a value.