Failed the WACK Test – How do I get more information?


Hello everyone,

So you finished your Windows Store app and are eager to get it into the Store – but it failed the Windows App Certification Kit (WACK) test and the results do not provide sufficient information about the reason of the failure. What can you do to get more details?

The first thing to look at are the internal logs of WACK. You can find them in the following folder: C:\Users\<user>\AppData\Local\Microsoft\AppCertKit (Especially interesting are the .txt files. Look out for the name of the test that your app failed.)

If you need to review the content of the xperfTemp.txt file, e.g. for the performance launch test, you may find that it is empty, or that its content does not reflect the output from the test anymore. That is because it is a temporary file and gets overwritten by different tests. In this case, you have two options:

  1. You can run exactly the same command that is listed in the (internal) log file, which WACK used to extract the timing information from the .ETL file
  2. You can run the test that failed manually, and only that test

To run a single test manually, you can use the following command: Appcert.exe test -apptype windowsstoreapp -packagefullname <full package id> -reportoutputpath c:\temp\testpackage.xml –testid <test id>

You can look up the test id here: C:\Program Files (x86)\Windows Kits\8.0\App Certification Kit\configuration.xml (E.g. the index for the Performance Launch test is 43)

I hope this helps, should your app ever fail a test in WACK and you don’t know why.


Helge Mahrt