Well it's not really an error. Each operator works with a local data set and doesn't see other operator's updates until the data is refreshed. When an operator commits a change, the warning msg occurs if another operator has already modified the same record.
Occasionally, a problem with an index file may generate bogus locking errors. You can often clear them by:
1. Get everybody out of Approach
2. Take a backup
3. Open each dbf in turn directly in Approach
4. From the new apr, compress the dbf: File | User Setup | Approach Preferences | Database tab
5. Discard the apr without saving
Afterwards, check there are no .OYZ files present which indicate serious index problems.
Compressing a dbf physically removes records marked as deleted and rebuilds minimal index files. When you next open the apr, you may have to wait a few seconds while further SmartIndexes are built.
BTW, I have authored and published a component, DBFPack, to automate the compression process for multiple dbf files. An evaluation copy can be downloaded from my web site.
Paul Bent
Northwind IT Systems