@ben Hi sorry to hear you’re experiencing this problem.
It seems you’re using Pencil2D under Windows 10, if that’s the case please read this guide to prevent this from happening. Attached to the guide there’s a development build with an extra fix, but you need to follow the guide thoroughly first to lessen the permissions issue with the OS.
Please note though that this development version might not be entirely stable, or might have other problems, and if you have any issue with it please let us know.
You can also consider looking for the latest dev build in the Nightly build section of our download website Download | Pencil2D Animation