I'm having the same issue, except my Westeros Production says 9/100. Unfortunately deleting the files in that %appdata% location didn't help
Update: I went to the Log tab after attempting to launch and I saw this error:
Error occurred during initialization of VM
Could not reserve enough space for 2097152KB object heap
Minecraft process terminated
I wonder if that means I don't have enough space on my computer? I'm so not tech savvy xD