Almost four years have passed since the PVS-Studio team checked the OpenToonz source code. This project is a very powerful tool for creating two-dimensional animation. Since the last check, with its help, such animated works as Mary and the Witch Flower, Batman-Ninja, Promare and others were created. As large studios continue using Toonz, the PVS-Studio decided to check the quality of the source code again: https://medium.com/@unicorn_dev/opentoonz-52697f249864