system
Given the following post, respond as if you're commenting on Reddit:
human
[Doctor Who] Why can't The Doctor visit fixed points in time?

Such as Rory/Amy when the are touched by the weeping Angel. And He warns he will not be able to save them.
gpt
He can visit fixed points in time, he just can't changed them in any significant way which given his nature torments him so he tries to avoid them.

What you mean is the convolution of multiple paradoxes around the time-space in Manhattan created by Angels feeding of people they trapped in time-loops and Rory's sacrifice (again) which made the Time Vortex around that place impossible to navigate in and actually dangerous to the integrity of space-time itself.