title: How to debug: w3wp.exe process was terminated due to a stack overflow (works on one machine but not another)
body: <p><strong>The problem</strong><br>
  I have an ASP.NET 4.0 application that crashes with a stack overflow on one computer, but not another. It runs fine on my development environment. When I move the site to the production server, it throws a stack overflow exception (seen in event log) and the w3wp.exe worker process dies and is replaced with another. </p>
  
  <p><strong>What I've tried so far</strong><br>
  For reference, I used the debug diagnostic tool to try to determine what piece of code is causing the overflow, but I'm not sure how to interpret the output of it. The output is included below. </p>
  
  <p><strong>How might an ASP.NET website cause a stack overflow on one machine but not on another?</strong><br>
  Experienced leads are appreciated. I'll post the resulting solution below the answer that leads me to it.</p>
  
  <p><strong>Debug Output</strong>  </p>
  
  <p>Application: w3wp.exe Framework Version: v4.0.30319 Description: The process was terminated due to stack overflow.</p>
  
  <pre><code>In w3wp__PID__5112__Date__02_18_2011__Time_09_07_31PM__671__First Chance Stack Overflow.dmp the assembly instruction at nlssorting!SortGetSortKey+25 in C:\WINDOWS\Microsoft.NET\Framework\v4.0.30319\nlssorting.dll from Microsoft Corporation has caused a stack overflow exception (0xC00000FD) when trying to write to memory location 0x01d12fc0 on thread 16
  Please follow up with the vendor Microsoft Corporation for C:\WINDOWS\Microsoft.NET\Framework\v4.0.30319\nlssorting.dll
  Information:DebugDiag determined that this dump file (w3wp__PID__5112__Date__02_18_2011__Time_09_07_31PM__671__First Chance Stack Overflow.dmp) is a crash dump and did not perform any hang analysis. If you wish to enable combined crash and hang analysis for crash dumps, edit the IISAnalysis.asp script (located in the DebugDiag\Scripts folder) and set the g_DoCombinedAnalysis constant to True.
  Entry point   clr!ThreadpoolMgr::intermediateThreadProc 
  Create time   2/18/2011 9:07:10 PM 
  Function     Arg 1     Arg 2     Arg 3   Source 
  nlssorting!SortGetSortKey+25     01115a98     00000001     0651a88c    
  clr!SortVersioning::SortDllGetSortKey+3b     01115a98     08000001     0651a88c    
  clr!COMNlsInfo::InternalGetGlobalizedHashCode+f0     01115a98     05e90268     0651a88c    
  mscorlib_ni+2becff     08000001     0000000f     0651a884    
  mscorlib_ni+255c10     00000001     09ed57bc     01d14348    
  mscorlib_ni+255bc4     79b29e90     01d14350     79b39ab0    
  mscorlib_ni+2a9eb8     01d14364     79b39a53     000dbb78    
  mscorlib_ni+2b9ab0     000dbb78     09ed57bc     01ff39f4    
  mscorlib_ni+2b9a53     01d14398     01d1439c     00000011    
  mscorlib_ni+2b9948     0651a884     01d143ec     7a97bf5d    
  System_ni+15bd65     6785b114     00000000     09ed5748    
  System_ni+15bf5d     1c5ab292     1b3c01dc     05ebc494    
  System_Web_ni+6fb165 
  ***These lines below are repeated many times in the log, so I just posted one block of them
  1c5a928c     00000000     0627e880     000192ba    
  1c5a9dce     00000000     0627e7c4     00000000    
  1c5a93ce     1b3c01dc     05ebc494     1b3c01dc    
  1c5a92e2
  .....(repeated sequence from above)
  System_Web_ni+16779c     1b338528     00000003     0629b7a0    
  System_Web_ni+1677fb     00000000     00000017     0629ac3c    
  System_Web_ni+167843     00000000     00000003     0629ab78    
  System_Web_ni+167843     00000000     00000005     0629963c    
  System_Web_ni+167843     00000000     00000001     0627e290    
  System_Web_ni+167843     00000000     0627e290     1a813508    
  System_Web_ni+167843     01d4f21c     79141c49     79141c5c    
  System_Web_ni+1651c0     00000001     0627e290     00000000    
  System_Web_ni+16478d     00000001     01ea7730     01ea76dc    
  System_Web_ni+1646af     0627e290     01d4f4c0     672c43f2    
  System_Web_ni+164646     00000000     06273aa8     0627e290    
  System_Web_ni+1643f2     672d1b65     06273aa8     00000000    
  1c5a41b5     00000000     01d4f520     06273aa8    
  System_Web_ni+18610c     01d4f55c     0df2a42c     06273f14    
  System_Web_ni+19c0fe     01d4fa08     0df2a42c     06273e5c    
  System_Web_ni+152ccd     06273aa8     05e9f214     06273aa8    
  System_Web_ni+19a8e2     05e973b4     062736cc     01d4f65c    
  System_Web_ni+19a62d     06a21c6c     79145d80     01d4f7fc    
  System_Web_ni+199c2d     00000002     672695e8     00000000    
  System_Web_ni+7b65cc     01d4fa28     00000002     01c52c0c    
  clr!COMToCLRDispatchHelper+28     679165b0     672695e8     09ee2038    
  clr!BaseWrapper&lt;Stub *,FunctionBase&lt;Stub *,&amp;DoNothing&lt;Stub *&gt;,&amp;StubRelease&lt;Stub&gt;,2&gt;,0,&amp;CompareDefault&lt;Stub *&gt;,2&gt;::~BaseWrapper&lt;Stub *,FunctionBase&lt;Stub *,&amp;DoNothing&lt;Stub *&gt;,&amp;StubRelease&lt;Stub&gt;,2&gt;,0,&amp;CompareDefault&lt;Stub *&gt;,2&gt;+fa     672695e8     09ee2038     00000001    
  clr!COMToCLRWorkerBody+b4     000dbb78     01d4f9f8     1a78ffe0    
  clr!COMToCLRWorkerDebuggerWrapper+34     000dbb78     01d4f9f8     1a78ffe0    
  clr!COMToCLRWorker+614     000dbb78     01d4f9f8     06a21c6c    
  1dda1aa     00000001     01b6c7a8     00000000    
  webengine4!HttpCompletion::ProcessRequestInManagedCode+1cd     01b6c7a8     69f1aa72     01d4fd6c    
  webengine4!HttpCompletion::ProcessCompletion+4a     01b6c7a8     00000000     00000000    
  webengine4!CorThreadPoolWorkitemCallback+1c     01b6c7a8     0636a718     0000ffff    
  clr!UnManagedPerAppDomainTPCount::DispatchWorkItem+195     01d4fe1f     01d4fe1e     0636a488    
  clr!ThreadpoolMgr::NewWorkerThreadStart+20b     00000000     0636a430     00000000    
  clr!ThreadpoolMgr::WorkerThreadStart+3d1     00000000     00000000     00000000    
  clr!ThreadpoolMgr::intermediateThreadProc+4b     000c3470     00000000     00000000    
  kernel32!BaseThreadStart+34     792b0b2b     000c3470     00000000    
  NLSSORTING!SORTGETSORTKEY+25In w3wp__PID__5112__Date__02_18_2011__Time_09_07_31PM__671__First Chance Stack Overflow.dmp the assembly instruction at nlssorting!SortGetSortKey+25 in C:\WINDOWS\Microsoft.NET\Framework\v4.0.30319\nlssorting.dll from Microsoft Corporation has caused a stack overflow exception (0xC00000FD) when trying to write to memory location 0x01d12fc0 on thread 16
  </code></pre>