Troubleshooting

Importing — part 5 of 5

SymptomWhat it means
N media file(s) could not be downloadedThe URLs are dead at the source -- old CDNs disappear (every distilleryimage*.instagram.com link from 2012 resolves to nothing). The posts were written without those images; nothing to fix on your side.
Tumblr API returned 401 UnauthorizedWrong TUMBLR_API_KEY or blog name.
Many skipped (not a post) from a WXRNormal -- WordPress's own menu items and revisions travel in the same export. Attachments and pages have their own lines, and so does every custom post type, named after itself (wp:portfolio) -- if you recognize one of those as a section of your blog, its posts stayed behind.
skipped (error) with stderr linesThose items were malformed at the source; the rest imported. Re-run after a fix overwrites in place.
The source stopped answering after N item(s)The platform died mid-run. Everything written so far is saved; re-run once the source recovers -- posts are matched on their source id, so nothing duplicates.
cannot move '<slug>' into <year>: a different post already owns ...A re-imported item's date moved into a year where another post has the same slug. That one item is skipped, nothing was touched; rename one of the slugs and re-run.
The same id-less post appears twice after a re-importThe item carries neither guid nor link, so it can't be matched. Delete the extra copy; better, give the item a guid at the source.
The deploy stops with a % increase warningThe guard doing its job after a bulk change -- re-run with --force once the numbers look right.
An imported post shows a shifted datesite.timezone wasn't set and the machine runs UTC -- set it and rebuild; stored dates don't change, only the rendered day.