repository error after apt-get update

Hello Everybody,from yesterday I get always the same message when I try to update the system,I have to install the drivers for the FT232 interface to manage the spindle. especially the pcgminer cgminer packages, but since yesterday I always get the server is unavailable.

anyone have the same problems? or am I doing something wrong?

thanks to whoever replies

I don't know what the problem is, the server seems to be up:
www.linuxcnc.org/dists/buster/