Hello, ROBLOXians.
1. Re-install ROBLOX by going to www.roblox.com/install/.
2. Clear your browser's cache. Google Chrome: Go to the three bars>History>Clear all browsing data... Internet Explorer: Go the the washer icon>Internet Options>Delete...
3. Restore defaults in studio.
4. Add ROBLOX to exceptions on your Anti-Virus, Anti-Malware and Firewall. If you need help, feel free to PM me.
5. Make sure your drivers are up-to-date and your Adobe Flash Player, Java and Direct X is up-to-date.
May or may not work.