FASM finds error in "pop"

Why does'nt FASM compile it? Sad
It finds an error in "pop cx" Sad
But why?
Code:
        org        100h                 ; !-?@>3@0<<0
        mov        ah,2                 ; DC=:F8O 02 ?@5@K20=8O 1Ah
        int        1Ah                  ; ?>;CG8BL B5:CI55 2@5<O
        mov        ch,dh                ; A>E@0=8BL B5:CICN A5:C=4C 2 !
        mov        cl,0100b             ; CL = A>AB>O=85 A25B>48>4>2 :;0280BC@K
main_loop:
        call       change_LEDs          ; CAB0=>28BL A25B>48>4K 2 A>>B25BAB288 A CL
        shl        cl,1                 ; A;54CNI89 A25B>48>4,
        test       cl,1000b             ; 5A;8 548=8F0 2KH;0 2 18B 3,
        jz         continue
        mov        cl,0001b             ; 25@=CBL 55 2 18B 0,
continue:
        mov        ah,1                 ; ?@>25@8BL, =5 1K;0 ;8 =060B0 :;028H0,
        int        16h
        jnz        exit_loop            ; 5A;8 40 - 2K9B8 87 ?@>3@0<<K
        push       cx
        mov        ah,2                 ; DC=:F8O 02 ?@5@K20=8O 1Ah
        int        1Ah                  ; ?>;CG8BL B5:CI55 2@5<O
        pop        AE
        cmp        ch,dh                ; A@02=8BL B5:CICN A5:C=4C 2 DH A !,
        mov        ch,dh                ; A:>?8@>20BL 55 2 ;N1>< A;CG05,
        je         continue             ; 5A;8 MB> 1K;0 B0 65 A0<0O A5:C=40 - =5
                                        ; ?5@5:;NG0BL A25B>48>4K,
        jmp        short main_loop      ; 8=0G5 - ?5@5:;NG8BL A25B>48>4K
exit_loop:
        mov        ah,0                 ; 2KE>4 87 F8:;0 - 1K;0 =060B0 :;028H0,
        int        16h                  ; AG8B0BL 55
        ret                             ; 8 7025@H8BL ?@>3@0<<C

; ?@>F54C@0 change_LEDs
; CAB0=02;8205B A>AB>O=85 A25B>48>4>2 :;0280BC@K 2 A>>B25BAB288 A G8A;>< 2 CL
proc change_LEDs
        call       wait_KBin            ; >6840=85 2>7<>6=>AB8 ?>AK;:8 :><0=4K
        mov        al,0EDh
        out        60h,al               ; :><0=40 :;0280BC@K EDh
        call       wait_KBin            ; >6840=85 2>7<>6=>AB8 ?>AK;:8 :><0=4K
        mov        al,cl
        out        60h,al               ; =>2>5 A>AB>O=85 A25B>48>4>2
        ret
endp

; ?@>F54C@0 wait_KBin
; >6840=85 2>7<>6=>AB8 22>40 :><0=4K 4;O :;0280BC@K
proc wait_KBin
        in         al,64h               ; ?@>G8B0BL A;>2> A>AB>O=8O
        test       al,0010b             ; 18B 1 @025= 1?
        jnz        wait_KBin            ; 5A;8 =5B - 640BL,
        ret                             ; 5A;8 40 - 2K9B8
endp