>It is also possible that the same error occurs twice (in sequence), the 1st time in the program (that triggers the error handler) and the second time in the error routine (error that cannot be trapped any more). Under the circumstances, it may have something to do with system resources (it could be file handles if your error handler attempts to create/open any files), rebooting will refresh them and your application will run until the resources are exhausted again.
>Just another thought...
>Sorin
>
>>Does anyone have any inforamtion about this error? Does Files=Whatever in config.sys in Win95 have any affect.
>>
>>We have an application written in VFP3.0 that communicates with up to 30 devices through a serial port and an RS232/RS485 adapter. This application needed to work in Windows3.1 and Win95 so we wrote two DLL's that call windows API functions depending on which operating system is in use. They are straight calls. The only reason we wrote DLL's was because VFP does not handle or pass structures.
>>
>>In most cases everything works fine but customers complain about this error occasionaly. We have told them to increase the Files setting and reboot. I suspect that it is actually the reboot that fixes the problem. It seems to occur mostly when there are communications errors.
>>
>>This error completely bypasses our error handler so we don't know what code is barfing and have no way to collect clues. We have not found a way to duplicate the error here.
>>
>>Please help?

Thanks to every one who replied. As luck would have it, I found the problem. A customer sent in a device for repair that seemed to generate the conditions under which the problem occured. With this I was able to isolate the problem to a line of code and then it was pretty obvious what was going on. I was creating a string 128 characters long and passing the string by reference to the DLL. We don't expect any responses longer than that. The device in question was generating trash characters and the responses were in the thousands of characters. Naturally this was going to corrupt memory.