.data
    normal: .ascii "aaa/0aab/0aac/0"
    save: 

.text
    main:
        # Load address of the string "aaa/0aab/0aac/0" into $a1
        la $a1, normal
        # Skip the first string "aaa/" (4bytes)
        addi $a1, $a1, 4
        # Load the second string "aab/0" into $a0
        lw $a0, ($a1)
        # Store the second string at the address of "save"
        sw $a0, save

        # Print the second string
        # Prepare syscall code for printing a string (4)
        li $v0, 4
        # Load the address of the string to be printed
        la $a0, save
        # Make the syscall
        syscall

        # Exit the program
        li $v0, 10
        syscall

Wrote this program, it is very simple, it gets the second item from the string vector, saves it in the save adress and then prints it. It runs into an error at line 14 (sw $a0, save). What is the problem here, even my teacher cant figure it out. Is it an issue with MARS or what is it?