Hi everyone!

Out of the blue, my forms started showing the following error. I'm using Umbraco version 7.15.4 assembly 1.0.7381.11453 and Forms 7.4.1 :

[NullReferenceException: Object reference not set to an instance of an object.] Umbraco.Forms.Data.StringHelper.ParseRecordPlaceholders(String value, IRecord record) +237 Umbraco.Forms.Data.StringHelper.ParsePlaceHolders(HttpContext context, Record record, String value) +74 Umbraco.Forms.Data.StringHelper.ParsePlaceHolders(Record record, String value) +39 Umbraco.Forms.Core.Services.WorkflowService.ExecuteWorkflows(List1 workflows, RecordEventArgs e) +454 Umbraco.Forms.Core.Services.WorkflowService.ExecuteWorkflows(Record record, Form form, FormState state, Boolean editMode) +184 Umbraco.Forms.Web.Services.RecordService.Submit(Record record, Form form) +605 Umbraco.Forms.Web.Controllers.UmbracoFormsController.SubmitForm(Form form, FormViewModel model, Dictionary2 state, ControllerContext context) +1680 Umbraco.Forms.Web.Controllers.UmbracoFormsController.GoForward(Form form, FormViewModel model, Dictionary2 state) +58 Umbraco.Forms.Web.Controllers.UmbracoFormsController.HandleForm(FormViewModel model, Boolean captchaIsValid) +435 lambda_method(Closure , ControllerBase , Object[] ) +143 System.Web.Mvc.ActionMethodDispatcher.Execute(ControllerBase controller, Object[] parameters) +14 System.Web.Mvc.ReflectedActionDescriptor.Execute(ControllerContext controllerContext, IDictionary2 parameters) +157 System.Web.Mvc.ControllerActionInvoker.InvokeActionMethod(ControllerContext controllerContext, ActionDescriptor actionDescriptor, IDictionary2 parameters) +27 System.Web.Mvc.Async.<>c.<BeginInvokeSynchronousActionMethod>b__9_0(IAsyncResult asyncResult, ActionInvocation innerInvokeState) +22 System.Web.Mvc.Async.WrappedAsyncResult2.CallEndDelegate(IAsyncResult asyncResult) +29 System.Web.Mvc.Async.WrappedAsyncResultBase1.End() +49 System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeActionMethod(IAsyncResult asyncResult) +32 System.Web.Mvc.Async.<>c__DisplayClass11_0.<InvokeActionMethodFilterAsynchronouslyRecursive>b__0() +58 System.Web.Mvc.Async.<>c__DisplayClass11_2.<InvokeActionMethodFilterAsynchronouslyRecursive>b__2() +228 System.Web.Mvc.Async.<>c__DisplayClass11_2.<InvokeActionMethodFilterAsynchronouslyRecursive>b__2() +228 System.Web.Mvc.Async.<>c__DisplayClass11_2.<InvokeActionMethodFilterAsynchronouslyRecursive>b__2() +228 System.Web.Mvc.Async.<>c__DisplayClass11_2.<InvokeActionMethodFilterAsynchronouslyRecursive>b__2() +228 System.Web.Mvc.Async.<>c__DisplayClass11_2.<InvokeActionMethodFilterAsynchronouslyRecursive>b__2() +228 System.Web.Mvc.Async.<>c__DisplayClass7_0.<BeginInvokeActionMethodWithFilters>b__1(IAsyncResult asyncResult) +10 System.Web.Mvc.Async.WrappedAsyncResult1.CallEndDelegate(IAsyncResult asyncResult) +10 System.Web.Mvc.Async.WrappedAsyncResultBase1.End() +49 System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeActionMethodWithFilters(IAsyncResult asyncResult) +34 System.Web.Mvc.Async.<>c__DisplayClass3_6.<BeginInvokeAction>b__4() +35 System.Web.Mvc.Async.<>c__DisplayClass3_1.<BeginInvokeAction>b__1(IAsyncResult asyncResult) +100 System.Web.Mvc.Async.WrappedAsyncResult1.CallEndDelegate(IAsyncResult asyncResult) +10 System.Web.Mvc.Async.WrappedAsyncResultBase1.End() +49 System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeAction(IAsyncResult asyncResult) +27 System.Web.Mvc.<>c.<BeginExecuteCore>b__152_1(IAsyncResult asyncResult, ExecuteCoreState innerState) +11 System.Web.Mvc.Async.WrappedAsyncVoid1.CallEndDelegate(IAsyncResult asyncResult) +29 System.Web.Mvc.Async.WrappedAsyncResultBase1.End() +49 System.Web.Mvc.Controller.EndExecuteCore(IAsyncResult asyncResult) +45 System.Web.Mvc.<>c.<BeginExecute>b__151_2(IAsyncResult asyncResult, Controller controller) +13 System.Web.Mvc.Async.WrappedAsyncVoid1.CallEndDelegate(IAsyncResult asyncResult) +22 System.Web.Mvc.Async.WrappedAsyncResultBase1.End() +49 System.Web.Mvc.Controller.EndExecute(IAsyncResult asyncResult) +26 System.Web.Mvc.Controller.System.Web.Mvc.Async.IAsyncController.EndExecute(IAsyncResult asyncResult) +10 System.Web.Mvc.<>c.<BeginProcessRequest>b__20_1(IAsyncResult asyncResult, ProcessRequestState innerState) +28 System.Web.Mvc.Async.WrappedAsyncVoid1.CallEndDelegate(IAsyncResult asyncResult) +29 System.Web.Mvc.Async.WrappedAsyncResultBase`1.End() +49 System.Web.Mvc.MvcHandler.EndProcessRequest(IAsyncResult asyncResult) +28 System.Web.Mvc.MvcHandler.System.Web.IHttpAsyncHandler.EndProcessRequest(IAsyncResult result) +9 System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +9847493 System.Web.HttpApplication.ExecuteStepImpl(IExecutionStep step) +50 System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +163