This would be because for 4.3.2 Blizzard decided to re-organize and optimize the Data folder of the PTR.
Certain patch files were merged into existing ones and a new world-2.MPQ file has appeared.
It's having to re-download a lot of data as technically it's all new information to the installer. Not sure why it can't just copy the data from existing files and write it into new files but there you are.
Unable to find streaming info for "Data\enUS\OldWorld-enUS.MPQ". (OpenRepackTarget::Validate)
AFAIK This is error is when your installing the 4.3 PTR for the first time.
Seems to be a bug in the installer as it's happened twice before. Have emailed the zombie sheep about it, we just need to wait till he's in the office to forward onto the right bodies.
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