Visual Foxpro 7 App Crashes Consistently

[BryonB]

We've been trying to update a VFP 7.0 application to run in Terminal Server. After making the adjustments we thought would be needed (local application data storage, etc.) we're finding that the application is crashing consistently after running for only a couple of minutes.

When we first encountered this, we didn't even see an error message - the program would just "go away". It turned out that DrWatson was set up not to display any messages (unfortunately, this is a production box). I did a registry tweak to prevent DrWatson from automatically doing anything, and now I can see an Application Error dialog before the program closes. It just says that an instruction at "0x77fcb673" referenced memory at "0x000000010", and that the memory could not be "read."

I've tried running FileMon while the application runs, but there doesn't seem to be a consistent pattern of open files when the error occurs.

No errors/warnings are shown in the event log.

So far I have not been able to get any other information about what VFP might be doing at the time, since DrWatson does not even complete its log of the error, it only writes the first two lines.

It seems to crash whether I run it remotely, or at the console.

The strange thing is that if I start the application from within the Foxpro development environment, it runs fine.

We're running under:
Windows 2000 Advanced Server SP2 + pre-SP3 "hot" patches.
Citrix Metaframe 1.8 SP3
Visual Foxpro 7.0 SP1
2GB memory

If anyone has any suggestions, I would greatly appreciate hearing them!

 

[richcoll]

Is this application querying a FoxPro database? If so, then if this database resides on a network share then Windows 2000 Server has this rather annoying habit of disconnecting the connection when some users logoff.

To test this theory, move the database locally onto the Citrix server's hard drive, and re-test.

For more information, see thread48-91199 "Visual Foxpro and Metaframe 1.8 for Win2k - Error 1104"

 

[BryonB]

Our tables are on the Citrix server's local hard drive. I had seen that other thread, so did not try to put them on a network drive for now.

It appears that memory address 0x00000010 may be in the I/O range of the DMA memory controller on the PCI bus. Could this be a device driver issue?

 

[BryonB]

OK. I waited through the process of requisitioning a test server, and separate licenses to set it up. I did a clean install of Windows 2000 Server SP2, Citrix MetaFrame XPe SP1, FR1.

The application still crashes!

DrWatson never finishes writing anything to its log file, so I set WinDbg as the postmortum debugger, and from there I can at least poke around a bit to try to determine what was running.

It seems to be getting a fatal exception c00000005 error somewhere in NTDll.dll/Kernel32.dll.

This application has run without any errors of this sort on both Windows 2000/Windows 95 machines for over a year.

It ONLY seems to get this error when running under Terminal Server/Citrix.

This new server is a single-CPU machine.

Does anyone have any clues as to what else I can try?

 

[BryonB]

Well, we finally found and solved this problem. It turns out that a programmer who used to work here wrote code in one procedure that declared the RPCRT4.DLL with a hard-coded path (C:\WINNT\SYSTEM32...).

After removing this and recompiled the application, the application runs fine with any version of the Citrix client.

Whew!! To those of you who responded with ideas, THANK YOU!