This article was previously published under Q264867
This article lists the possible causes of data corruption in Visual FoxPro. The article also includes some tools for fixing data corruption.
Although this is by no means a complete list of every possible cause of corruption, it is meant to be a starting point for troubleshooting data corruption problems in Visual FoxPro.
Possible causes for data corruption are:
Abnormal termination of the application while manipulating data. This would include loss of power, voltage spikes, internal consistency errors, page faults, and fatal exception errors.
Substandard or faulty network components: Because FoxPro handles data so quickly, it can stress the network. These components may include network drivers, network interface cards, cabling, hubs, and switches.
Data storage components: Storage devices should be checked regularly for errors and fragmentation.
File locking issues: If one user performs an action that results in a table's memo file being locked, and a second user attempts to open the same table and access the memo field information, the second user may open the memo file with an incorrect blocksize, resulting in memo file corruption. See the "References" section in this article for details.
Conflicting software: Software such as Antivirus packages, screen savers, and terminate-and-stay-resident applications (TSRs) can cause conflicts with Visual FoxPro that could cause data corruption.
Incompatible video drivers: Certain video drivers can cause FoxPro to become unstable and terminate abnormally. See the "References" section in this article for more details.
Network Settings and Service Packs: Make sure that your servers are running the latest service packs, check client settings (such as caching), and even try switching network client drivers (such as from the Novell Netware client to the Microsoft client for Netware).
For additional information on the causes of corruption, click the following article numbers to view the articles in the Microsoft Knowledge Base:
195405 FIX: Corrupt record added in grid using view with default value
95232 PRB: Video card causes GP faults or display problems
195623 FIX: Index corruption when table is used in read-only mode
164385 BUG: Large result sets may become corrupted in VFP
For additional information about specific methods for fixing corruption, click the following article numbers to view the articles in the Microsoft Knowledge Base:
193952 How to troubleshoot to resolve suspected corruption
168762 How to fix Index corruption at run time with Visual FoxPro
189458 INFO: Third Party Utility Repairs FoxPro Record and Memo Data
Microsoft Visual FoxPro 3.0 Standard Edition, Microsoft Visual FoxPro 3.0b Standard Edition, Microsoft Visual FoxPro 5.0 Standard Edition, Microsoft Visual FoxPro 5.0a, Microsoft Visual FoxPro 6.0 Professional Edition, Microsoft Visual FoxPro 7.0 Professional Edition, Microsoft Visual FoxPro 8.0 Professional Edition, Microsoft Visual FoxPro 9.0 Professional Edition