Can't update firmware

[pcomud]

My prusa I3 Pro W can't update firm ware. As shown 1-4 pictures. I started with a complete connection (show in figure 1) . After that, I updated the firmware (show figure 2) . Display the confirmation window "Press OK" (Figure 3). Finally, the connection was lost (figure 4).
1. [url=https://uppicimg.com/v/oFiJT6tW][img]https://uppicimg.com/s/oFiJT6tW[/img][/url]
2. [url=https://uppicimg.com/v/sCLVHBeX][img]https://uppicimg.com/s/sCLVHBeX[/img][/url]
3. [url=https://uppicimg.com/v/BY1gk29r][img]https://uppicimg.com/s/BY1gk29r[/img][/url]
4. [url=https://uppicimg.com/v/VqkcfiK9][img]https://uppicimg.com/s/VqkcfiK9[/img][/url]

[Gingko]

Have you tried to set baud rate as 256000?
When updating firmware use 256000,
printing use 250000.

[pcomud]

250000

[pcomud]

use 250000.

[pcomud]

Now it's okay.
After upload firmware by arduino "firmware No.13".
After that, update again through the program "EasyPrint3D".

[pcomud]

Now it's okay.
After upload firmware by arduino "firmware No.13".
After that, update again through the program "EasyPrint3D".