ERROR: Workflow failed on start

I was getting below error while starting of workflow.

Workflow:System.Workflow.ComponentModel.Compiler.WorkflowValidationFailedException: The workflow failed validation.     at System.Workflow.Runtime.WorkflowDefinitionDispenser.ValidateDefinition(Activity root, Boolean isNewType, ITypeProvider typeProvider)     at System.Workflow.Runtime.WorkflowDefinitionDispenser.LoadRootActivity(Type workflowType, Boolean createDefinition, Boolean initForRuntime)     at System.Workflow.Runtime.WorkflowDefinitionDispenser.GetRootActivity(Type workflowType, Boolean createNew, Boolean initForRuntime)     at System.Workflow.Runtime.WorkflowRuntime.InitializeExecutor(Guid instanceId, CreationContext context, WorkflowExecutor executor, WorkflowInstance workflowInstance)     at System.Workflow.Runtime.WorkflowRuntime.Load(Guid key, CreationContext

I spend lots of time to find out exact resolution for workflow failed error, but I couldn’t get solution, below are some of the reference link which talks causing of issue due to migration from visual studio 2005 to 2008 workflow project, but in my case, I have created workflow into visual studio 2008 only, some articles were talking about adding some line into solution project, but that’s also not working for me.

Reference Link:

http://blog.hhebnes.no/?tag=/workflows

http://www.eggheadcafe.com/software/aspnet/31975863/sharepoint-workflow-upgra.aspx

http://geekswithblogs.net/SoftwareDoneRight/archive/2007/12/12/condition-not-found.aspx

At the last for resolving my issue, I have created new workflow file, one thing I have observed here – if I am going to change main default file name for workflow file from workflow.cs to something else, then sometime it will mess up workflow. So I would recommend not changing workflow.cs file name.

:)