python コードのエラーについて

コードと同じファイルに画像があるのに画像のようなエラーが表記されます。
原因は何でしょうか？
ちなみに下がコードです。

python
1コードimport tkinter 
2import random
3
4index=0
5timer=0
6score=0
7hisc=1000
8difficulty=0
9tsugi=0
10
11cursor_x=0
12cursor_y=0
13mouse_x=0
14mouse_y=0
15mouse_c=0
16
17def mouse_move(e):
18    global mouse_x,mouse_y
19    mouse_x=e.x
20    mouse_y=e.y
21
22def mouse_press(e):
23    global mouse_c
24    mouse_c=1
25
26neko=[]
27check=[]
28for i in range(10):
29    neko.append([0,0,0,0,0,0,0,0])
30    check.append([0,0,0,0,0,0,0,0])
31
32def draw_neko():
33    cvs.delete("NEKO")
34    for y in range(10):
35        for x in range(8):
36            if neko[y][x]>0:
37                cvs.create_image(x*72+60,y*72+60,image=img_neko[neko[y][x]],tag="NEKO")
38
39def check_neko():
40    for y in range(10):
41        for x in range(8):
42            check[y][x]=neko[y][x]
43
44    for y in range(1,9):
45        for x in range(8):
46            if check[y][x]>0:
47                if check[y-1][x]==check[y][x] and check[y+1][x]==check[y][x]:
48                    neko[y-1][x]=7
49                    neko[y][x]=7
50                    neko[y+1][x]=7
51
52    for y in range(10):
53        for x in range(1,7):
54            if check[y][x]>0:
55                if check[y][x-1]==check[y][x] and check[y][x+1]==check[y][x]:
56                    neko[y][x-1]=7
57                    neko[y][x]=7
58                    neko[y][x+1]=7
59
60    for y in range(1,9):
61        for x in range(1,7):
62            if check[y][x]>0:
63                if check[y-1][x-1]==check[y][x] and check[y+1][x+1]==check[y][x]:
64                    neko[y-1][x-1]=7
65                    neko[y][x]=7
66                    neko[y+1][x+1]=7
67                if check[y+1][x-1]==check[y][x] and check[y-1][x+1]==check[y][x]:
68                    neko[y+1][x-1]=7
69                    neko[y][x]=7
70                    neko[y-1][x+1]=7
71
72def sweep_neko():
73    num=0
74    for y in range(10):
75        for x in range(8):
76            if neko[y][x]==7:
77                neko[y][x]=0
78                num=num+1
79    return num
80    
81def drop_neko():
82    flg=False
83    for y in range(8,-1,-1):
84        for x in range(8):
85            if  neko[y][x] != 0 and neko[y+1][x]==0:
86                neko[y+1][x]=neko[y][x]
87                neko[y][x]=0
88                flg=True
89    return flg
90
91def over_neko():
92    for x in range(8):
93        if neko[0][x]>0:
94            return True
95    return False
96
97def set_neko():
98    for x in range(8):
99        neko[0][x]=random.randint(0,difficulty)
100
101def draw_txt(txt,x,y,siz,col,tg):
102    fnt=("Times New Roman",siz,"bold")
103    cvs.create_text(x+2,y+2,text=txt,fill="black",font=fnt,tag=tg)
104    cvs.create_text(x,y,text=txt,fill=col,font=fnt,tag=tg)
105
106def game_main():
107    global index,timer,score,hisc,difficulty,tsugi
108    global cursor_x,cursor_y,mouse_c
109    if index==0:
110        draw_txt("猫猫",312,240,100,"violet","TITLE")
111        cvs.create_rectangle(168,384,456,456,fill="skyblue",width=0,tag="TITLE")
112        draw_txt("Easy",312,420,40,"white","TITLE")
113        cvs.create_rectangle(168,528,456,600,fill="lightgreen",width=0,tag="TITLE")
114        draw_txt("Nowmal",312,564,40,"white","TITLE")
115        cvs.create_rectangle(168,672,456,744,fill="orange",width=0,tag="TITLE")
116        draw_txt("Hard",312,708,40,"white","TITLE")
117        index=1
118        mouse_c=0
119    elif index==1:
120        difficulty=0
121        if mouse_c==1:
122            if 168<mouse_x and mouse_x<456 and 384<mouse_y and mouse_y<456:
123                difficulty=4
124            if 168<mouse_x and mouse_x<456 and 528<mouse_y and mouse_y<600:
125                difficulty=5
126            if 168<mouse_x and mouse_x<456 and 672<mouse_y and mouse_y<744:
127                difficulty=6
128        if difficulty>0:
129            for y in range(10):
130                for x in range(8):
131                    neko[y][x]=0
132                mouse_c=0
133                score=0
134                tsugi=0
135                cursor_x=0
136                cursor_y=0
137                set_neko()
138                draw_neko()
139                cvs.delete("TITLE")
140                index=2
141    elif index==2:
142        if drop_neko()==False:
143            index=3
144        draw_neko()
145    elif index==3:
146        check_neko()
147        draw_neko()
148        index=4
149    elif index ==4:
150        sc = sweep_neko()
151        score=score+sc*difficulty*2
152        if score>hisc:
153            hisc=score
154        if sc>0:
155            index=2
156        else:
157            if over_neko()==False:
158                tsugi=random.randint(1,difficulty)
159                index=5
160            else:
161                index=6
162                timer=0
163        draw_neko()
164    elif index == 5:
165        if 24<=mouse_x and mouse_x<24+72*8 and 24<=mouse_x and mouse_y<24+72*10:
166            cursor_x=int((mouse_x-24)/72)
167            cursor_y=int((mouse_y-24)/72)
168            if mouse_c==1:
169                mouse_c=0
170                set_neko()
171                neko[cursor_y][cursor_x]=tsugi
172                tsugi=0
173                index=2
174        cvs.delete("CURSOR")
175        cvs.create_image(cursor_x*72+60,cursor_y+72+60,image=cursor,tag="CURSOR")
176        draw_neko()
177    elif index == 6:
178        timer = timer+1
179        if timer == 1:
180            draw_txt("GAME OVER",312,348,60,"red","OVER")
181        if timer == 50:
182            cvs.delete("OVER")
183            index=0
184    cvs.delete("INFO")
185    draw_txt("SCORE"+str(hisc),160,60,32,"blue","INFO")
186    draw_txt("HISC"+str(hisc),450,60,32,"yellow","INFO")
187    if tsugi>0:
188        cvs.create_image(752,128,image=img_neko[tsugi],tag="INFO")
189        root.after(100,game_main)
190
191root=tkinter.Tk()
192root.title("落ち物パズル「ねこねこ」")
193root.resizable(False,False)
194root.bind("<Motion>",mouse_move)
195root.bind("<ButtonPress>",mouse_press)
196cvs = tkinter.Canvas(root,width=912,height=768)
197cvs.pack()
198
199bg = tkinter.PhotoImage(file="neko_bg.png")
200cursor= tkinter.PhotoImage(file="neko_cursor.png")
201img_neko=[
202    None,
203    tkinter.PhotoImage(file="nako1.png"),
204    tkinter.PhotoImage(file="neko2.png"),
205    tkinter.PhotoImage(file="neko3.png"),
206    tkinter.PhotoImage(file="neko4.png"),
207    tkinter.PhotoImage(file="neko5.png"),
208    tkinter.PhotoImage(file="neko6.png"),
209    tkinter.PhotoImage(file="neko_niku.png")
210]
211
212cvs.create_image(456,384,image=bg)
213game_main()
214root.mainloop()
215