Pack server seems to be unreachable

Trying to install a pack I get

?- pack_install(liftcover).
% Contacting server at ...
ERROR: url `''' does not exist (status(503,first byte timeout))

Should be ok again. There was a problem with the pack backend.

There was a more persistent problem resulting from a corrupted file after a crash due to a power failure. It seems both backends are happy again.