There are 2 error messages that show up when the build server is not able to start a build. Here are ways to trouble shoot these cases.
Pre – checks to ensure that the setup is correct
Error: The build service could not validate the caller. Please ensure that the network connection between Build machine and Team foundation server is proper, and the caller is valid.
The build server is configured to bind to one TF Server only. The caller to the build server has to be the service account from the TF Server.
This error appears in 2 scenarios –
1. If the account is not in the build services group, and does not have the right permissions. The first error can be checked by ensuring that the prechecks are okay.
2. The server urls are different. One user might be connected to the Team foundation server using a short name say like MyMachine – the server url would translate to http://MyMachine:8080. The second user might be connected using a fully qualified string like “MyMachine.domain.com” and the server url would be http://MyMachine.domain.com:8080, or one could use an IP address which would result in the server url like http://127.x.x.x:8080 . In Beta3, these names were not resolved, so the tf server url’s have to match exactly for the build server to honor a request. The fix here is to use the type that works. This is an issue in beta3, and fixed post for RTM.
Error: TF42046: The build service used in the build process is not reachable. This error occurs when either the build machine is off-line, the required service is not running, Team Build is not installed on the build machine, Team Build is configured for a different Team Foundation Server or the network is not available. Please contact your Team Foundation Server administrator to verify that Team Build is correctly installed and running.
This error is seen in many scenario’s.
Most of these errors can be avoided by the pre-checks. Item 5 occurs in the case where an build machine which was used with another TF Server ( say beta2 TF server ), is now set to being used for the new Team foundation server. In these cases, the “AllowedTeamServer” key in the registry at HKCU\Software\microsoft\visualstudio\8.0\teambuild for the Build service account, or the “AllowedTeamServer” key in the TFSBuildService.exe.config contain the allowed team server. If this is no longer in use, delete the registry entry.
Additional debugging
If none of the above work – you can enable tracing on the TF Server by setting the “tracewriter” value to true in the web.config, and setting the switches values to 3. Please send the exception trace in the log file to the Visual Studio Team System forum.