活字格自定义WEBAPI调用出错

各位大佬，本人在使用webapi的时候，发现一个问题。程序引用了第三方类库，运行时候报错。类库都有上传到项目中。求解答，万分感谢。
Request Exception Happened-------------------------------
Path/customapi/zkapi/testpostapi
{
  "ClassName": "System.ArgumentException",
  "Message": "The specified invariant name 'System.Data.SqlClient' wasn't found in the list of registered .NET Data Providers.",
  "Data": null,
  "InnerException": null,
  "HelpURL": null,
  "StackTraceString": "   at System.Data.Common.DbProviderFactories.GetFactory(String providerInvariantName, Boolean throwOnError)
   at System.Data.Common.DbProviderFactories.GetFactory(String providerInvariantName)
   at FaceApi.SqlServerProvider.CreateDbProviderFactory()
   at System.Lazy`1.ViaFactory(LazyThreadSafetyMode mode)
--- End of stack trace from previous location where exception was thrown ---
   at System.Lazy`1.CreateValue()
   at System.Lazy`1.get_Value()
   at FaceApi.SqlServerProvider.CreateConnection()
   at FaceApi.DbContext.get_CreateCommand()
   at FaceApi.DbContext.Sql(String sql, Object[] parameters)
   at FaceApi.iZkFace.FnGetMacInfo()
   at FaceApi.iZkFace.GetUserListFromMac(Int32 macid)
   at FaceApi.zkapi.TestPostAPI()
   at Forguncy.KatanaMiddleware.j.a(HttpContext A_0)
   at Forguncy.KatanaMiddleware.j.InvokeAsync(HttpContext context)
   at Forguncy.KatanaMiddleware.i.InvokeAsync(HttpContext context)
   at Forguncy.Server2.KatanaMiddleware.StartPageMiddleware.InvokeAsync(HttpContext context)
   at ForguncyServerCommon.HttpHeaderMiddlewareBase.InvokeAsync(HttpContext context)
   at Forguncy.KatanaMiddleware.p.InvokeAsync(HttpContext context)",
  "RemoteStackTraceString": null,
  "RemoteStackIndex": 0,
  "ExceptionMethod": null,
  "HResult": -2147024809,
  "Source": "System.Data.Common",
  "WatsonBuckets": null,
  "ParamName": null
}