I have created a form, when upon submission passes the variables into a Laserfiche Workflow to fill out a PDF. Upon submission of the form, I am receiving an unexpected error [LFF502]. The workflow seems to be kicked off, and it completed the "Fill Out PDF Form" activity properly. I can't seem to decipher what is causing the error, any help is much appreciated! I have inserted the Windows Event Viewer Error below:

[502]: An unexpected error has occurred. [LFF502-UnexpectedError]

Details:
URL: /Forms/Form/Submit
Error: UnexpectedError
Date: 3/25/2019 3:44:52 PM (Eastern Standard Time)
HTTP Status Code: 500
Business Process ID: 44
User: [REDACTED]
IP: 10.94.59.6
Browser: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/73.0.3683.86 Safari/537.36
Business Process Name: Wire Transfer Request

Stack Trace:
Caught exception: Laserfiche.Forms.CommonUtils.Exceptions.LFFormsException
Message: An unexpected error has occurred. [LFF502-UnexpectedError]


Inner exception: System.NullReferenceException
Message: Object reference not set to an instance of an object.
   at Laserfiche.Forms.CommonUtils.SubmissionCache.Get[Type](String nameKey, String itemKey, String fieldKey)
   at E_Forms.Controllers.FormController.Thanks(String parentView, Int32 formId, Int32 submissionId, Int32 option, Boolean HideHeader, SubmissionDataSet submissionData, FormDataSet formData, Boolean inMobileIframe)
   at E_Forms.Controllers.FormController.Submit(FormCollection collection)
   at lambda_method(Closure , ControllerBase , Object[] )
   at System.Web.Mvc.ReflectedActionDescriptor.Execute(ControllerContext controllerContext, IDictionary`2 parameters)
   at System.Web.Mvc.ControllerActionInvoker.InvokeActionMethod(ControllerContext controllerContext, ActionDescriptor actionDescriptor, IDictionary`2 parameters)
   at System.Web.Mvc.Async.AsyncControllerActionInvoker.<BeginInvokeSynchronousActionMethod>b__39(IAsyncResult asyncResult, ActionInvocation innerInvokeState)
   at System.Web.Mvc.Async.AsyncResultWrapper.WrappedAsyncResult`2.CallEndDelegate(IAsyncResult asyncResult)
   at System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeActionMethod(IAsyncResult asyncResult)
   at System.Web.Mvc.Async.AsyncControllerActionInvoker.AsyncInvocationWithFilters.<InvokeActionMethodFilterAsynchronouslyRecursive>b__3d()
   at System.Web.Mvc.Async.AsyncControllerActionInvoker.AsyncInvocationWithFilters.<>c__DisplayClass46.<InvokeActionMethodFilterAsynchronouslyRecursive>b__3f()
   at System.Web.Mvc.Async.AsyncControllerActionInvoker.AsyncInvocationWithFilters.<>c__DisplayClass46.<InvokeActionMethodFilterAsynchronouslyRecursive>b__3f()
   at System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeActionMethodWithFilters(IAsyncResult asyncResult)
   at System.Web.Mvc.Async.AsyncControllerActionInvoker.<>c__DisplayClass21.<>c__DisplayClass2b.<BeginInvokeAction>b__1c()
   at System.Web.Mvc.Async.AsyncControllerActionInvoker.<>c__DisplayClass21.<BeginInvokeAction>b__1e(IAsyncResult asyncResult)