I am creating Sandbox solution to attach Event Receiver to Form Library.I want to debug the solution but it is giving me error

Unable to attach process 'SPUCWorkerProcess.exe' is not running on 'ServerName'

I have checked

1. SharePoint User Code Host service running in services
2. Microsoft SharePoint Foundation Sandboxed Code Service is running in Central Admin
3. In Central Administration -> Farm Management -< Manage User Soltuion -> Selected option All sandboxed code runs on the same machine as a request.

but still same issue exists