TFS 2010 Web Access “access denied” error

If you're getting "Access to the path 'C:\ProgramData\Microsoft\Team Foundation\Web Access\Cache' is denied" error when you try to access TFS 2010 Beta 2 via the Team Web Access, the problem most likely lies with missing NTFS permissions on the above-mentioned Cache folder. This problem often happens when you're running your TFS 2010 server on a domain controller, which is not ideal, but sometimes unavoidable, especially if you run all-in-one server setup.

There are two possible workarounds:

  1. First workaround is to assign Modify NTFS permissions on Cache folder on the TFS server to the service account used by SharePoint application pool in your TFS environment. Most likely, your SharePoint application pool (by default) runs under Network Service built-in account.
  2. Second workaround is changing SharePoint application pool to run under a domain account instead of Network Service account. I have read somewhere that this problem is caused by the fact that Network Service account cannot be added to a global group TFS_APPTIER_SERVICE_WPG, which is a domain group, not local to your TFS/DC server.

Note: If Cache folder does not exist, create one J