Same here : Cannot launch SweetHome 3D for monthes (since 5.3 release).

I did switch from a 2011 MacBook Air to a brand new MacBook Pro last month (macOS 10.12.6). I did reinstall SH3D (using homebrew cask), but the software remains locked on the splash screen.

I often search for an answer in those forums, I tried different fixes (no PlugIns folder in Package content folder, no log in my console, no extensions folder in ~/Library/Java), but nothing worked, even installing manually.

I was able to work around using the Java Web Start

… But that's not very handy