Under Windows 7 Projucer cannot update to 5.1.2/ It was crashed on update process
Try running the Projucer with admin privileges. I that doesn’t work, you’ll need to download the version manually from https://www.juce.com/get-juce/download
Try running the Projucer with admin privileges. I that doesn’t work, you’ll need to download the version manually from https://www.juce.com/get-juce/download