This error has popped up out of no where and is driving me mad!!!

If anyones got any advice it would be much appreciated. Basically this happens when i try and run my project through visual web developer. I've tried deleting my security.config and restarting iis and a few other things from googling but nothing has solved it. This is getting incredibly frustrated as its affecting my development.

An unhandled exception occurred and the process was terminated. Application ID: WebDev.WebServer40.exe Process ID: 7044 Exception: System.SystemException Message: Failed to create AppDomain. StackTrace: at System.Web.Hosting.ApplicationManager.CreateAppDomainWithHostingEnvironment(String appId, IApplicationHost appHost, HostingEnvironmentParameters hostingParameters) at System.Web.Hosting.ApplicationManager.CreateAppDomainWithHostingEnvironmentAndReportErrors(String appId, IApplicationHost appHost, HostingEnvironmentParameters hostingParameters) at System.Web.Hosting.ApplicationManager.GetAppDomainWithHostingEnvironment(String appId, IApplicationHost appHost, HostingEnvironmentParameters hostingParameters) at System.Web.Hosting.ApplicationManager.CreateObjectInternal(String appId, Type type, IApplicationHost appHost, Boolean failIfExists, HostingEnvironmentParameters hostingParameters) at System.Web.Hosting.ApplicationManager.CreateObject(String appId, Type type, String virtualPath, String physicalPath, Boolean failIfExists, Boolean throwOnError) at System.Web.Hosting.ApplicationManager.CreateObject(String appId, Type type, String virtualPath, String physicalPath, Boolean failIfExists) at Microsoft.VisualStudio.WebHost.Server.GetHost() at Microsoft.VisualStudio.WebHost.Server.OnSocketAccept(Object acceptedSocket) at System.Threading.QueueUserWorkItemCallback.WaitCallback_Context(Object state) at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean ignoreSyncCtx) at System.Threading.QueueUserWorkItemCallback.System.Threading.IThreadPoolWorkItem.ExecuteWorkItem() at System.Threading.ThreadPoolWorkQueue.Dispatch() at System.Threading._ThreadPoolWaitCallback.PerformWaitCallback() InnerException: System.OutOfMemoryException Message: Exception of type 'System.OutOfMemoryException' was thrown. StackTrace: at System.Security.Policy.PEFileEvidenceFactory.GetLocationEvidence(SafePEFileHandle peFile, SecurityZone& zone, StringHandleOnStack retUrl) at System.Security.Policy.PEFileEvidenceFactory.GenerateLocationEvidence() at System.Security.Policy.PEFileEvidenceFactory.GenerateEvidence(Type evidenceType) at System.Security.Policy.AssemblyEvidenceFactory.GenerateEvidence(Type evidenceType) at System.Security.Policy.Evidence.GenerateHostEvidence(Type type, Boolean hostCanGenerate) at System.Security.Policy.Evidence.GetHostEvidenceNoLock(Type type) at System.Security.Policy.Evidence.GetHostEvidence(Type type, Boolean markDelayEvaluatedEvidenceUsed) at System.Security.Policy.AppDomainEvidenceFactory.GenerateEvidence(Type evidenceType) at System.Security.Policy.Evidence.GenerateHostEvidence(Type type, Boolean hostCanGenerate) at System.Security.Policy.Evidence.GetHostEvidenceNoLock(Type type) at System.Security.Policy.Evidence.GetHostEvidence(Type type, Boolean markDelayEvaluatedEvidenceUsed) at System.Security.Policy.Evidence.GetHostEvidence[T]() at System.Web.Hosting.ApplicationManager.GetDefaultDomainIdentity() at System.Web.Hosting.ApplicationManager.CreateAppDomainWithHostingEnvironment(String appId, IApplicationHost appHost, HostingEnvironmentParameters hostingParameters