I think this error results only from an undefined 404 error page, which aolserver tries to redirect to, but upon not finding the page, repeatedly tries again. Gives up after 3 tries and produces its own 404 page.
Openacs4.6.3 has a parameter that defines the error page directory. Under serviceurl/admin/site-map goto set parameters of Main Site. Look at the GlobalURLStub parameter. Value defaults to /global.