We are in the process of upgrading to W-10.  One of our users is trying to test and is receiving the following:

faulting application name: runcobol.exe, version: 10.1.2006.516, time stamp: 0x4469702a faulting module name: ntdll.dll, version: 10.0.18362.387, time stamp: 0xa4208572 exception code: 0xc0000006 fault offset: 0x00071d40 faulting process id: 0x3ba8 faulting application start time: 0x01d58912c2f11422 faulting application path: x:\\long\\runcobol.exe faulting module path: c:\\windows\\system32\\ntdll.dll report id: 735818e3-2df2-4d96-9451-d34d05622742 faulting package full name: faulting package-relative application id:

Does anyone know what the problem is?

As you know, RM/COBOL 10.1 is a really ancient version, well out of support, and the proper answer is to upgrade to v12, which is fully tested and supported on Windows XP through Windows 10.

Did this customer's installation ever run on Windows 7 or are they migrating directly from XP? 

First, I'd suggest the user enable XP Compatibility Mode for RUNCOBOL.EXE to see if that helps.

If the program previously ran on Windows 7 or later, one possibility is that Windows 10 dropped support for SMB version 1 networking.  It can be re-enabled (search for "enable SMB v1 on Windows 10" for instructions), at the risk of downgrading security.

Finally, are there third-party non-COBOL program involved? The fault won't report if it's a DLL that's calling another DLL -- it gets blamed on the main program.

Any of the above are just band-aids and could stop working in future Win10 releases.  So upgrading is really the best option.

We are in the process of upgrading to v12.15.  I had received information under different discussion thread that v10.1 would run on Windows 10 without having to upgrade RM/COBOL. 

This particular error has been resolved.

All future development will be done using v12.15 but we are not planning on recompiling the entire code base.  Initial testing has shown that v10 and v12 (32-bit compiles) work well together.