Does my theory re corrupt FPT make sense?

[OldxBaser]

We have noticed an increased report of Error 41 (missing or corrupt FPT) over the last half year from our client base.

Most of our users run our very large application in a shared network environment, on various combinations of platforms. Some have dozens of users logged in simultaneously with no problems; file/record locking works consistently well.

However, this slight increase in reports of a 'corrupt' or 'missing' FPT seems to have coincided with the increased attention to Windows security, especially with Vista and with various AVS software.

I don't know the real sequence of file-opening when VFP opens a DBF that has a CDX and FPT. Is it possible that the DBF opens first, and then it detects the need to open the associated FPT and CDX before allowing access to the DBF data? If so, what if the resident real-time AVS is still scanning the FPT when a VFP command tries to open a file in exclusive mode? Would this not generate an error 41?

We have had some occurrences of client data sent to us that fails with this error on the client network but runs perfectly here, and we are trying to find a generic resolve to this.

Any comments on this?

 

[JRB-Bldr]

One rule for minimizing problems with a VFP application is to exclude all DBF, CDX,& FPT files from real-time virus checking.

Real-time virus checking has been the cause of more than one person's problems.

Merely put those extensions into the EXCLUDE settings.

Try that and see if the problem goes away.

If not, then "resident real-time AVS is still scanning the FPT" is not related to the problem.

Good Luck,
JRB-Bldr

 

[Mike Lewis]

I agree completely with JRB-Bldr. If you suspect the anti-virus is causing the problem, the first thing you should do is to temporarily exclude DBFs, FPTs and CDXs from the AV check. If the problem goes away, you know it's the AV that's the culprit, and you can exclude those file types on a permanent basis.

In fact, you should exclude them anyway. It could take a considerable amount of time to scan one of those files, and it's not going to make any differenece to security, since DBFs etc. don't hold executable code.

Mike

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Mike Lewis (Edinburgh, Scotland)

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