In some rare occassion .NET Remoting service may throw a 404 error. Besides the obvious cause of URL misconfiguration as the error implied, the error can also be caused by the size of the Remoting call. If the total size of the objects being sent to the Remoting server (not client) exceeds the configuration limit, IIS would throw a 404 error, even though the error has little to do with File not Found.
To fix this error, one of the ways is through changing the Web.config to allow larger request size limit, this can be achieved by changing the setting under system.webServer / security / requestFilter / requestLimits @ maxAllowedContentLength . For example:
<system.webServer> <security> <requestFiltering> <requestLimits maxAllowedContentLength="56700000" /><!-- in bytes --> </requestFiltering> </security> </system.webServer>
Related Post: Large file uploads in ASP.NET