GPU/driver issue or corrupted profile. Solution: Delete the folder %APPDATA%\Cisco Packet Tracer\7.2.2\ptp.config and restart.
The most secure and official way to get Packet Tracer for free is through the Cisco Networking Academy (NetAcad) .
Support for single-board computers (like Raspberry Pi simulations) and microcontrollers (Arduino style), allowing for Python and JavaScript scripting.
New themes, the ability to align workspace objects, and a feature to name and deploy devices to specific racks.