Good day, 

A couple of users have received the error An unexpected error has occurred. [LFF502-UnexpectedError] when submitting from Internet Explorer but not when using Chrome. We are using Forms 10.2. 

This occurs on 2 separate Processes

When I look at the event viewer it posts the following information - 

An unexpected error has occurred. [LFF502-UnexpectedError]

Details:
URL: /Forms/Form/Submit
Error: UnexpectedError
Date: 2017/02/16 11:55:41 AM (South Africa Standard Time)
HTTP Status Code: 500
Business Process ID: 5
User: KDZA\michellef
IP: 172.20.180.209
Browser: Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 10.0; WOW64; Trident/7.0; .NET4.0C; .NET4.0E; .NET CLR 2.0.50727; .NET CLR 3.0.30729; .NET CLR 3.5.30729; InfoPath.3)
Business Process Name: Purchase Inquiry

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 E_Forms.Models.ViewModels.Form.Submit.RetrieveDataFromForm(HttpRequestBase request, Dictionary`2 formdata, Boolean SaveAll)
   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.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.<>c__DisplayClass33.<BeginInvokeActionMethodWithFilters>b__32(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)

Thanks