well there is an easy option for you to update the flashplayer the miniclient.

first you have to find the install folder of adobe flashplayer on your pc which is normally here (C:\Windows\SysWOW64\Macromed\Flash)

the folder should look something like this

now you have to copy this file i selected (called pepflashplayer32_versionnumber.dll)

next step is finding the folder where you have your naruto online client installed and go into the PepperFlash folder

in there is just 1 file called "pepflashplayer32.dll" you insert the newer version you just copied from the adobe flashplayer folder

now just delete the file that was already there and rename the new file so that its called just "pepflashplayer32.dll" (meaning you remove the version number from the name)

and thats all you have to do, now if you start the naruto online client it uses the new flashpayer

oh you used the 64 bit version of the flashplayer that is installed on a different path

C:\Windows\System32\Macromed\Flash - contains the 64-bit files

C:\Windows\SysWOW64\Macromed\Flash - contains the 32-bit files

if you for some reason dont have the 32-bit version installed you have to go to the official adobe flashplayer website: https://get.adobe.com/en/flashplayer/ and install the full programm that contains both versions