Ubisoft released a few updates for the PC version shortly after launch (e.g., version 1.01), which addressed crashes, audio glitches, and controller issues. However, no comprehensive "final patch" was ever released that fixes all known bugs.
It sounds like you're looking for a bug fix patch for Prince of Persia: The Forgotten Sands . Here's what you need to know: prince of persia forgotten sands bug fix patch
Would you like detailed steps for any of these? Ubisoft released a few updates for the PC
Let me know which level or platform you're on, and I can give you a workaround or save file fix. which addressed crashes