1. Go into Your home and rename .eteks folder to .eteks1;
2. Execute SweetHome3D by double-click and accept "Execute";
3. Help->About to see what You run (if You run something);
4. If it run delete .eteks and rename .eteks1 to .eteks;
5. Run again;
6. If NOT OK You have to retry and dig deeper or wait another help.