I was adding a new tab to a doctype when I got this error (I've only seen it once, and it didn't cause any issues as far as I can tell, but thought I'd report it anyway):

Server Error in '/' Application.

The process cannot access the file 'C:\Repos\[path_redacted]\App_Data\Temp\uSync.SourceInfo.xml' because it is being used by another process.

Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. 

Exception Details: System.IO.IOException: The process cannot access the file 'C:\Repos\[path_redacted]\App_Data\Temp\uSync.SourceInfo.xml' because it is being used by another process.

Source Error: 

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.

Stack Trace: 


[IOException: The process cannot access the file 'C:\Repos\[path_redacted]\App_Data\Temp\uSync.SourceInfo.xml' because it is being used by another process.]
   System.IO.__Error.WinIOError(Int32 errorCode, String maybeFullPath) +10900997
   System.IO.File.InternalDelete(String path, Boolean checkHost) +11206992
   System.IO.File.Delete(String path) +21
   jumps.umbraco.usync.helpers.SourceInfo.Save() +876
   jumps.umbraco.usync.SyncDocType.ContentTypeService_SavedContentType(IContentTypeService sender, SaveEventArgs`1 e) +1268
   Umbraco.Core.Events.TypedEventHandler`2.Invoke(TSender sender, TEventArgs e) +0
   Umbraco.Core.Events.EventExtensions.RaiseEvent(TypedEventHandler`2 eventHandler, TArgs args, TSender sender) +48
   Umbraco.Core.Services.ContentTypeService.Save(IContentType contentType, Int32 userId) +444
   umbraco.cms.businesslogic.web.DocumentType.Save() +549
   umbraco.controls.ContentTypeControlNew.btnNewTab_Click(Object sender, EventArgs e) +216
   System.Web.UI.WebControls.Button.OnClick(EventArgs e) +9615678
   System.Web.UI.WebControls.Button.RaisePostBackEvent(String eventArgument) +103
   System.Web.UI.WebControls.Button.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument) +10
   System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument) +13
   System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData) +35
   System.Web.UI.<ProcessRequestMainAsync>d__14.MoveNext() +5226

Version Information: Microsoft .NET Framework Version:4.0.30319; ASP.NET Version:4.0.30319.34009

Umbraco 7.0.4. uSync 2.0.0rc4. Visual Studio 2013.