If you see repeated program crashes and errors about corrupt or inaccessible data files, it is usually due to environmental factors outside of the Quickstore program. This will typically happen more often when your setup has one or more additional lane licenses, rather than everything being on a single machine. We very strongly recommend against wireless networks for the client machines to have proper access to the database.
Beyond that, we have seen issues specifically with Microsoft Security Essentials and Norton AntiVirus, but the same would apply to other virus protection as well. If the anti-virus is scanning the data files, it will cause the data access to slow down to the point that some data files are updated, but writing to other data files fails. After this has happened, the indexes will be out of sync with each other, leading to corruption and the program having missing records, leading to errors in various parts of the program.
You must make sure when installing and configuring the anti-virus that you set up exclusions to prevent it from scanning the C:\WQS directory on the server, the mapped network drive on the client, all files named *.tps, and applications MAIN.EXE and WQS.EXE. With all of those exclusions in place, if Norton works properly, it will minimize its impact on Quickstore. The program will still cause server load, and it will sometimes attempt to scan the Quickstore files even though they should be excluded.
We have seen multiple issues with Microsoft Security Essentials ignoring the exclusions and continuing to cause data issues. For this reason, we have to recommend that Microsoft Security Essentials be completely removed from all systems running QuickStore AND from any other computers operating on the same network. We also recommend avoiding Avast, Trend Micro, and Kaspersky, as they all have network scanning features that will slow down file access if you have multiple workstations, leading to the same problems as those caused by MSE.
AVG has been seen to work successfully for some customers. There is a free version, but if you are using the paid AVG Internet Security version, make sure to enable file sharing in the settings, in addition to the exclusions mentioned above for Norton.
You should also be sure to never to have multiple anti-virus programs active on the server, as the increased load of more than one program trying to scan the same files at the same time is sure to cause server load that will impact other programs.