Continuous Integration build succeeds, Manual build fails

Continuous Integration build succeeds, Manual build fails

My Team Project consists of a Web Forms application and WCF Services, in
two separate solutions (the WCF services are hosted on a server within the
domain, the web app is in the DMZ). I have two build definitions for my
Team Project: a CI build and a manual build Yesterday I merged a branch
back into my trunk to prepare for a deployment. When I checked in my merge
the CI build kicked off...and succeeded. So then I queued the manual build
(the manual build is what ends up on prod server). The manual build
failed. It fails everytime I run it now, however the CI build succeeds
every time. The error from the build log is pasted below. I don't know how
I broke this build, and I'm confused as to why the CI build succeeds but
the manual build fails (same build definition except the drop location is
different and the trigger is different).
Error:
Exception Message: Access to the path 'C:\Builds\1\My Web App\My Web
App\Sources\MyAppWcfServices\Services\Messages' is denied. (type
UnauthorizedAccessException) Exception Stack Trace: at
System.IO.__Error.WinIOError(Int32 errorCode, String maybeFullPath) at
System.IO.FileSystemEnumerableIterator1.CommonInit() at
System.IO.FileSystemEnumerableIterator1..ctor(String path, String
originalUserPath, String searchPattern, SearchOption searchOption,
SearchResultHandler`1 resultHandler, Boolean checkHost) at
System.IO.Directory.InternalGetFileDirectoryNames(String path, String
userPathOriginal, String searchPattern, Boolean includeFiles, Boolean
includeDirs, SearchOption searchOption, Boolean checkHost) at
System.IO.Directory.InternalGetDirectories(String path, String
searchPattern, SearchOption searchOption) at
Microsoft.TeamFoundation.Common.FileSpec.DeleteDirectoryInternal(String
path) at
Microsoft.TeamFoundation.Common.FileSpec.DeleteDirectoryInternal(String
path) at
Microsoft.TeamFoundation.Common.FileSpec.DeleteDirectoryInternal(String
path) at
Microsoft.TeamFoundation.Common.FileSpec.DeleteDirectoryInternal(String
path) at Microsoft.TeamFoundation.Common.FileSpec.DeleteDirectory(String
path, Boolean recursive) at
Microsoft.TeamFoundation.Build.Workflow.Activities.DeleteDirectory.Execute(CodeActivityContext
context) at
System.Activities.CodeActivity.InternalExecute(ActivityInstance instance,
ActivityExecutor executor, BookmarkManager bookmarkManager) at
System.Activities.Runtime.ActivityExecutor.ExecuteActivityWorkItem.ExecuteBody(ActivityExecutor
executor, BookmarkManager bookmarkManager, Location resultLocation)
Things I've read/tried:
TFS 2012 Build "Access to Path Denied"
Tool to find duplicate copies in a build (I didn't run the tool, couldn't
find a log file named like the example...confused)
I do not have my obj or bin directories in version control. This build
definition has been working great for months, up until yesterday. I'm not
sure what happened when I merged that would've caused this. There were no
conflicts in my merge, it was easy peasy....until I tried to build.