Same issue, looking at the log file this is what iv found
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2017-05-13 18:19:32,318 INFO fa.check Checking FA for: faf and map None
2017-05-13 18:19:32,318 INFO fa.check Version unknown, assuming latest
2017-05-13 18:19:32,319 INFO fa.check Updating FA for mod: faf, version None
2017-05-13 18:19:32,319 INFO fa.check Writing fa_path.lua config file.
2017-05-13 18:19:33,323 INFO fa.updater Updater: Downloading
http://content.dev.faforever.
com/faf/xdelta/effects.3677.nxt-effects.3681.nxt.xdelta
2017-05-13 18:19:33,642 ERROR __main__ Uncaught exception
Traceback (most recent call last):
File "src\fa\updater.py", line 660, in readDataFromServer
File "src\fa\updater.py", line 593, in handleAction
File "src\fa\updater.py", line 609, in applyPatch
File "C:\Miniconda\lib\shutil.py", line 119, in copy
File "C:\Miniconda\lib\shutil.py", line 82, in copyfile
IOError: [Errno 2] No such file or directory: 'C:\\ProgramData\\FAForever\\cache\\patchedFile'