We catch this error sporadically. Does anyone know what could it be?

The URL give by our error logging get this weird url for this error :

http://ourWebSite.com/ScriptResource.axd?d=-TlQhVhw2O9j_FRLgdQvFzJxWKYVH6aV62Jse0uO_9PoMsQJaDGiZYtRoBbTATQiWul69JuMDMqOA-yDDycgyNFrGPA_wlnKXZEyWGfJeCg1&t=3717b609

And the error is :

Error : This is an invalid script resource request.

We also get the stacktrace :

System.Web.HttpException: This is an invalid script resource request. at System.Web.Handlers.ScriptResourceHandler.Throw404() at System.Web.Handlers.ScriptResourceHandler.ProcessRequest(HttpContext context) at System.Web.Handlers.ScriptResourceHandler.System.Web.IHttpHandler.ProcessRequest(HttpContext context) at System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)

What could it be? And how can it be solve?

c# visual-studio-2010 asp.net-4.0
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