A while back I had found in my Firefox>Add-ons>Plugins an outdated version of Adobe flash player. The info for it showed the file name. So after doing a search for the file on my computer I found it was in the Arc plugins folder. So I deleted it and Firefox no longer showed the extra outdated plugin.
Several days ago Arc went to update when I launched it but immediately gave me an error saying 1 or more files are missing or corrupt and the client needs to repair itself. So I thought nothing of it.
Today I was looking at my browser plugins and found this outdated flash player. I searched my PC for the file and found, again, that it was in the Arc plugin folder. So I deleted it and my browser no longer showed the outdated plugin anymore.
After this I went to launch Arc and got the error message again saying it had missing or corrupt files. After letting Arc repair itself I went into the Arc plugins folder and sure enough, the file that is an outdated flash plugin was back and my web browser was showing it again.

Adobe flash player version that Arc insists on installing: Shockwave Flash 16.0.0.235
Current version of flash: Shockwave Flash 18.0.0.160 (checked for updates before posting this and this is the most recent version Adobe seems to have available)
Location in Windows 7 64bit: C:\Program Files (x86)\Perfect World Entertainment\Arc\plugins
File name: NPSWF32.dll
What has been happening since Arc reinstalled this outdated flash player: Every time I exit the game I get a Window's message saying the game client stopped responding with the option to find a solution and shut it down or just shut it down.
Someone had mentioned Arc using outdated flash a while back. After deleting the file a while back it didn't return and everything was fine until a few days ago.
Edit: Yep. Deleted the file in the Arc plugins folder and again when launching the client it says "Some files are missing or corrupted. Your Arc installation will now be repaired."
Edit: removed angry stuffs