In the last few days my site started to throw the generic asp.net error page when I'd try to visit it. So I'd go into the web.config and change "RemoteOnly" to "Off" and then the site would come up fine. So the act of altering the web.config forced a recompile and the error went away. But it seems to be happening every morning. I checked the event log and am seeing a lot of these:

Message: System.Web.HttpException: Could not load type ''. ---> System.ArgumentException: String cannot have zero length. at System.Reflection.Assembly._GetType(String name, Boolean throwOnError, Boolean ignoreCase) at System.Web.Compilation.BuildManager.GetType(String typeName, Boolean throwOnError, Boolean ignoreCase) --- End of inner exception stack trace --- at System.Web.Compilation.BuildManager.GetType(String typeName, Boolean throwOnError, Boolean ignoreCase) at DotNetNuke.Framework.Reflection.CreateType(String TypeName, String CacheKey, Boolean UseCache, Boolean IgnoreErrors)