I'm sorry but everything Starky just said is no help for me.
I downloaded the game about a month ago (playernet also). Yesterday i had the same problem with patching like everyone else in this thread. Deleted the game and playernet. Downloaded playernet, waited 4h for arcadia to download and pressed 'play' when it was done. Client started and patching also, from version 8.0.sth. After 1h i had version 9.0.1.1103.en and game started to download/check/idk something from version 6.4.0.2749, after it finished "copying ...\more_01_upd.exe" stopped at 20%. I've waited around 1h and got a little annoyed cuz it was 2.00AM already and still nothing. I wanted to turn it off but my girlfriend said "don't touch anything, they've said on the forum that it needs some time" so i left it for the night. I woke up this morning and after 8h of sleeping it's still freaking 20%!!
I dont have any antivirus/firewall turned on.
I have windows 8.
I did restart the computer after deleting game and before downloading playernet again.
Funny thing is that my girlfriend patched the game with no problem. The only differences are that she has windows 7, antivirus turned on, and she have the game since may 2015, she just didnt played it and she patched it a month ago and downloaded playernet cuz she read somewhere here that without it she'll have problems.
This game is not worth my nerves. -.-