I can have no idea what you tried or why you got that unrelated message.
My advice above considers that you are already comfortable to config:export and config:import without issue and are able to re-run migrations with said exported, edited, and re-imported migration yaml scripts.
Try (re-)installing the bootstrap barrio theme? Run config:export with it installed so theme settings are included in the export (then hopefully things won't break upon re-importing again).
This definitely fixes the problem for me. Thanks a lot!
It depends on a few things which of the 2 to use, but see if you can stick with the one that ran the previous time where everything was successful except for the files. One way to tell which ran, if you have migrate_plus module installed (if you don't, install it and try again), will be at Structure > Migrations. In there will be migration-specific errors logged for each migration you ran (if migrate_plus was installed prior to running the migrations).
Also with migrate_plus installed, after running drush migrate:upgrade with "--configure-only" those migrations become defined in the active configuration. You will have to export your active configuration to get access to them. e.g. drush config:export. When you export your configuration everything comes out in yaml files. You'll be looking for files named "migrate_plus.migration.______________.yaml". Probably "migrate_plus.migration.upgrade_d7_file.yaml" if I had to guess because that is more common. The Structure > Migrations page I mentioned has stats that should help show what has run too.
After exporting, check your sync folder for the yaml files and review/edit as necessary. Use absolute paths for file locations for best results. Make the necessary changes and then import the configuration back in (drush config:import) to affect the migration. And of course clear caches.
Hope that helps, if you weren't using migrate_plus that should be a game changer.
Which
It doesn't sound too bad actually, you've got everything but the files? Check:
- the upgrade_d7_file migration (or upgrade_d7_file_private). Make sure directory locations in your migration files are correct. (At this point consider hard-coding the locations)
- In the file migration yaml, usually migrate_plus.migration.upgrade_d7_file.yml, look for the `source_base_path` key. It's a constant and needs to point at your old sites/default/files folder or a copy of it, and use an absolute path.
- Review what is configured in the `source_full_path` key further down, and make sure that constant is set up for success and will concat with 'filepath' from the source using a '/' delimiter. If it's yet quite a default migration without crazy changes, you may not need to touch that bit. Just the `source_base_path`.
- File locations can potentially be affected during migration depending on your D7 vs. D10 sites/default/files location and settings and which has jurisdiction. They could also be affected by other migrations (if those migrations migrate file settings or paths).
- The file migration will have to be run first before the node one(s).
Good luck!