i was working on a hosted solution running on FM 16 server on a Windows 2012 server. It was about 10pm, and the server has a backup schedule that runs at 9pm, so I opened an hour-old backup on the server (via RDC) to retrieve some field values I had accidentally overwritten on the live hosted copy at around 10.
The server has a copy of FM 16.0.4 Advanced I use to open the backups. When I opened the 9PM backup, several tables were missing... the tables existed, but the Manage Database window said no fields were defined. I discovered, closing and reopening the file, that the problem would disappear or reappear randomly every time I reopened it. When the problem was happening, layouts based on those tables showed "<field missing>" for all fields.
I recovered the file and the recovery showed no errors. I opened the recovered file a few times, and the same problem was still present: sometimes tables suddenly showed 0 fields, sometimes they were fine, with no apparent rhyme or reason.
I was able to get some screenshots. Here are two screenshots of the exact same file, with no changes having been made to it except for closing and reopening it, taken less than 45 seconds apart, showing the same table ("RL", the second table under the "Ledgers" empty table) having both 0 and 57 fields defined:
Here are two consecutive screenshots from the recovered file, again showing the RL table's fields disappearing and reappearing within 45 seconds, with no changes except for the file having been closed and reopened again between the screenshots:
This appears to be completely sporadic. I couldn't spot any pattern to whether the RL table would have 0 or 57 fields defined after I closed and reopened the files, and it didn't happen frequently enough for me to get more than these screenshots of it, but it did happen several other times of many repeated closing and reopenings of the file, and with different tables at different times.
Obviously this is a serious concern. This is for a client, and I need to be able to assure them their backups are viable and right now I'm not convinced they are, and recovery didn't help the problem.
EDIT: I copied the original pre-recovery file to my Mac and opened and closed it a few times in Mac FMPA 16.0.4, and the problem didn't seem to recur.