Memory gates checking failed because the free memory (n bytes) is less than 5% of total memory.

Ever had this horrendous error?

WebHost failed to process a request.
 Sender Information: System.ServiceModel.ServiceHostingEnvironment+HostingManager/45653674
 Exception: System.ServiceModel.ServiceActivationException: The service '/YourServiceName.svc' cannot be activated due to an exception during compilation.  The exception message is: Memory gates checking failed because the free memory (186429440 bytes) is less than 5% of total memory.  As a result, the service will not be available for incoming requests.  To resolve this, either reduce the load on the machine or adjust the value of minFreeMemoryPercentageToActivateService on the serviceHostingEnvironment config element.. ---> System.InsufficientMemoryException: Memory gates checking failed because the free memory (186429440 bytes) is less than 5% of total memory.  As a result, the service will not be available for incoming requests.  To resolve this, either reduce the load on the machine or adjust the value of minFreeMemoryPercentageToActivateService on the serviceHostingEnvironment config element.
   at System.ServiceModel.Activation.ServiceMemoryGates.Check(Int32 minFreeMemoryPercentage, Boolean throwOnLowMemory, UInt64& availableMemoryBytes)
   at System.ServiceModel.ServiceHostingEnvironment.HostingManager.CheckMemoryCloseIdleServices(EventTraceActivity eventTraceActivity)
   at System.ServiceModel.ServiceHostingEnvironment.HostingManager.EnsureServiceAvailable(String normalizedVirtualPath, EventTraceActivity eventTraceActivity)
   --- End of inner exception stack trace ---
   at System.ServiceModel.ServiceHostingEnvironment.HostingManager.EnsureServiceAvailable(String normalizedVirtualPath, EventTraceActivity eventTraceActivity)
   at System.ServiceModel.ServiceHostingEnvironment.EnsureServiceAvailableFast(String relativeVirtualPath, EventTraceActivity eventTraceActivity)
 Process Name: iisexpress
 Process ID: 992

If you don’t want to scroll, the relevant part is:

Memory gates checking failed because the free memory (n bytes) is less than 5% of total memory.

That is indeed an ugly error to see. Its precursor is that you sit waiting all day for your computer to do anything at all. Switching between windows becomes a 30 minute task. It also takes about 30 minutes to write a single line of code, if you’re lucky. (And 10 minutes before the debugger launches your code.)

I’m getting more RAM tomorrow, but should you also need to run a webservice despite all your common sense telling that there isn’t enough memory to do so, just add this to the system.serviceModel section of your config file:

<serviceHostingEnvironment multipleSiteBindingsEnabled="true" minFreeMemoryPercentageToActivateService="0" />

Again, if you are as lazy to scroll as I am to wrap that to more than one line, the relevant part is:

minFreeMemoryPercentageToActivateService=”0″