Fuslogvw.exe tool for .Net does not show UI

Question

I'm trying to use fuslogvw.exe on a Win 2008 R2 system. It shows the process started and using CPU but no UI appears. I've tried the 32bit and 64bit version in and not in admin mode but no luck. I don't see anything in the event log as a problem.

Answer 1

If you cannot get the UI to work, it is not actually needed to configure and view the fusion logs. You can set the fusion log settings in the registry under the HKEY_LOCAL_MACHINE\Software\Microsoft\Fusion key, and then view the logs directly from the directory you have configured (as they are just HTML files).

If you want to configure the logs using the registry, you need to set the following keys (from here):

• LogFailures = 1 (DWORD Value)
  This turns on failure logging so that failed attempts to locate all assemblies are logged.

• LogResourceBinds = 1 (DWORD Value)
  This turns on failure logging so that failed attempts to locate satellite assemblies are logged. This is not logged by default.

• ForceLog = 1 (DWORD Value)
  This turns on logging for all assembly binds - both failures and successes. By default, only failures are logged. This is useful if you want to verify that an assembly is loading from a specific directory instead of from the global assembly cache.

• LogPath = "C:\fusionlogs\" (String Value)
  If you want to view the fusion logs easily, set the LogPath to a directory to output them to. By default the log files go into the Temporary Internet Files folder of the current user’s profile. For an ASP.Net or a .Net Windows service application, the only way to view the fusion log is to use this option. This is because they run as users other than the current user. The directory specified must already exist and have appropriate file permissions to be written to. For ASP.Net applications, the ASPNET user must have write permission to the directory. If the permissions are wrong, there will be no log output.

Answer 2

I recently ran into the exact same issue. fuslogvw.exe would start but seemingly freeze on startup.

As it turns out, I had forgotten to turn off logging last time I was checking binding logs. So I now had in the range of 40000 folders in Default and a similar amount in Native (and hundreds of thousands of log files). I can only assume that the log viewer was trying to load all of these up as it was starting and that's what stopped it in its tracks.

Deleted the logs and the log viewer starts up as expected.