I recently profiled some web applications using Visual Studio 2012, a vsp (Visual Studio Profile) file was generated as a result of the profiling session. I could successfully open the vsp file in Visual Studio 2012 as expected but when I tried to open the vsp file in Visual Studio 2010 the VS2010 IDE crashed. As a responsible citizen I raised bug # 762202 on Microsoft Connect site using the Microsoft Visual Studio 2012 Feedback Client. Note – In case you didn’t already know, VSP generated in Visual Studio 2012 is not backward compatible. Please refer below for the steps to reproduce the issue and the resolution of the connect bug. 1. Behaviour and Steps to Reproduce the Issue Description I have generated a vsp file by using the Visual Studio 2012 Standalone profiler. When I try and open the vsp file in Visual Studio 2010 the IDE crashes. I understand that a vsp generated by using VS 2012 cannot be opened in VS 2010, but the IDE crashing is not the behaviour I would expect to see. Steps to Reproduce the Issue 1. Pick up the Stand lone profiler from the VS 2012 installation media. The folder has both x 64 and x86 installer, since the machine I am using is x64 bit. I have installed the x64 version of the standalone profiler. 2. I have configured the system path by setting the 'environment variable' path to where the profiler is installed. In my case this is, C:\Program Files (x86)\Microsoft Visual Studio 11.0\Team Tools\Performance Tools 3. Created a new environment variable _NT_SYMBOL_PATH and set its value to CACHE*C:\SYMBOLSCACHE;SRV*C:\SYMBOLSCACHE*HTTP://MSDL.MICROSOFT.COM/DOWNLOAD/SYMBOLS;\\FOO\BUILD1234 4. Open up CMD as an administrator and run 'VSPerfASPNETCmd /tip http://localhost:56180/ /o:C:\Temp\SampleEISK.vsp' 5. This generates the following message on the cmd Microsoft (R) VSPerf ASP.NET Command, Version 11.0.0.0 Copyright (C) Microsoft Corporation. All rights reserved. Configuring and attaching to ASP.NET process. Please wait. Setting up profiling environment. Starting monitor. Launching ASP.NET service. Attaching Monitor to process. Launching Internet Explorer. The profiler is attached to ASP.net. Please run your application scenario now. Press Enter to stop data collection... 6. I perform certain actions and then I come back to the cmd and hit enter to shut down the profiling. Once I do this, the following message is written to the cmd, Press Enter to stop data collection... Profiling now shut down. Report file "C:\Temp\SampleEISK.vsp" was generated. Running VsPerfReport, packing symbols into the .VSP. Shutting down profiling and restarting ASP.NET. Please wait. Restarting w3wp.exe. 7. I look in the C:\Temp folder and I can see the SampleEISK.vsp file generated. I can successfully open this file in Visual Studio 2012. 8. When I am trying to open the vsp file in VS 2010 the VS 2010 IDE crashes. Kaboooom! What I would expect to happen I expect to receive a message "VS 2010 does not support the vsp file generated by VS 2012". What actually happened The VS 2010 IDE crashed 2. Resolution This is a valid bug! However, there isn’t much value in releasing a hotfix for this issue. Refer below to the resolution provided by the Visual Studio Profiler Team. Thank you for taking the time to report this issue. We completely agree that Visual Studio 2010 should not crash. However in this particular case this is not a bug we are going to retroactively release a fix to 2010 for at this point. Given that a fix would not unblock the scenario of opening a 2012 created file on Visual Studio 2010, and there is not an active update channel for Visual Studio 2010 other than manually locating and installing hot fixes, we will not be fixing this particular issue. Best Regards, Visual Studio Profiler Team Though it would be great to improve the behaviour however, this is not a defect that would stop you from progressing in any way. It’s important to note however that VSP files generated by Visual Studio 2012 are not backward compatible so you should refrain from opening these files in Visual Studio 2010.