Sadly in may region there is a recurring vandalism activity. Usually changesets occour in clusters of 5-10, making a response rather urgent before some mapper add further changesets to patch damages. IMHO we should not charge DWG of such local hassle, asking for a revert that, depending on DWG workload, could be performed days later.
So I’m looking for some clarification, since, trying OSM revert scripts  “complex_revert.pl”, execution log reports for instance:
cannot load version 2 of relation xxx (get): 404 Not Found
cannot load version 4 of way yyy (get): 404 Not Found
cannot load version 1 of node zzz (get): 404 Not Found
Until now, revert has been done in “dryrun” mode, so I wonder which results should I expect running effectively.
Should I go for simple reverts, starting from newest changeset? I tried this also, but several conflicts took me time, wondering if it were more practical manual adjustments and more OSM verisions…
Check which API you’re pointing at -it might be the dev API rather than the live one. Testing in non-dryrun mode on the dev API first is actually a good idea - go to https://api06.dev.openstreetmap.org/ , sign up, edit some data normally and revert it.
If not that, check you’re accessing https rather than http endpoints.