I have the same problem, I did a manual install of java 64-bit version but still the same...
Windows 8.1 64-bit
Java 8 update 25 (64-bit)
Java SE Development kit 8 update 20 (64-bit) (<- I'm using eclipse too)
Construct 2 r184 (64-bit)
Edit: Java 7 update 55 (64-bit) does work! You have to downgrade for now. Java deleted the download links from their website but you can still get it at:
Edit: If that link doesn't work:
I couldn't EnricoUniverse's link to work. To download it you have to go to this url:
Once there, search for "Java SE Runtime Environment 7u55". You have to click the radio button next to "Accept License Agreement" for the download to start. Then just install it, reboot C2, and the minifier will work again.