>>Hi All,
>>
>>Just in one week time we have two customers who have upgraded their workstations to Windows 10 calling for support because of our application errors out with a C5. The point of where it happens seems to be random.
>>
>>So far I have advised them to
>>- Check the network driver
>>- Check the printer driver and test while a different printer is the default printer
>>- Check the graphics driver and upgrade that if needed
>>- Disable the virus scanner temporarily to see whether it makes a difference
>>
>>- Delete the user profile on that machine and restart Windows
>>
>>Though I'm not able to check whether they all try that, it sounds like the problems are still there.
>>
>>This application has been very stable so far, and this particular build has been running on hundreds of workstations without a problemin the past, so I pretty much rule out it is our application.
>>We are running our application with SET RESOURCE OFF, so it also does not have anything to do with foxusers.dbf
>>
>>
>>Does anyone have the same experience with Windows 10 and a VFP9 app ?
>>
>>
>>Walter,
>
>c5 errors are not happening within foxpro, but within the c runtime and can both be caused by errors of the foxpro runtime or your code. If it's not corrupt foxuser.dbf, it can be dangling object references. The error could be in a child form and maybe is happening in the destroy of a child form? Dangling object references like this are a known cause of C*5 errors, and typically only manifest after repeated calls - always a real pain to figure out C5 errors because it's not a VFP error.

I've also seen situations where damaged indexes could result in C5 errors.