Revisiting this thread from a few years back:
Missing Key (https://forum1.pvxplus.com/index.php?topic=485.msg1510#msg1510)
We still have this "Correcting missing key" happen sporadically at a few customer sites.
These are all Windows systems.
It's (almost?) always when we delete several records from a file in rapid succession, like within a select loop. Even if this is some sort of indication of potential corruption, clicking "OK" and proceeding always seems to resolve whatever the problem was. I'd like to revisit whether a parameter or something can be added so PxPlus just does the "OK" action without any need to see/respond to a message box.
I can't answer your question since I have never seen this error. I never tried pvxplus in a live environment under Windows, so perhaps it's a Windows thing.
But what I can say is that I have experienced a bunch of issues with EFF files which results in corrupted data file and having to rebuild it which may or may not result with some data loss. Normally, a "keyed load" doesn't work. I use strictly VAR files with "extended record" enabled if needed for larger files. I do use EFF for statistics records that may require more indexes.
Since I have changed to VAR files, I've never seen any corrupted data. If you want peace of mind, don't use EFF files!