So in an update on this situation, we restored another backup, this time with the RC_Data_FMS folder. However, the links are still broken. I'd love to know if anybody's seen anything similar, and if so whether they were able to solve the problem.
It's going to be a big issue while we're still in development because the team is reluctant to test when so much data disappears with each new build. But going forward, they're concerned about the stability of the server since all the backups -- which are supposed to be giving them a level of protection -- are no good.
When you take a backup and open it locally, all the links will be broken. That's because 'local fmp' uses a slightly different path than 'hosted fmp'.
To check that: create a new record in the local copy and insert a container. Note where it puts it. The adjust the folder structure of the containers and they will show up.
It's one of the reasons to keep a separate file to store all the container fields with 1x1 relationships to the table where they belong to. That way you can reduce the likelihood of having to import them
Thanks Wim. I wasn't opening the file locally though. I restored the file and the data folder to the server and opened it through server. They're all still broken. I'm waiting for the IT guy to get in this morning to check permissions on the folder and its contents to see if that's the problem.