Custom WorkFlow Common Errors

Hello friends,
While creating a custom workflow I faced common errors which mostly occurs.It could be very useful for those who R invoed in custom workflow development.

Two errors are very likely to occur when developing workflows: Failed on Start and Error Occurred. This can be achived by checking the event log, but I find the log files are usually most helpful.These are located at: C:\Program Files\Common Files\Microsoft Shared\web server extensions\12\LOGS

Failed on Start: This error occurs due to unproper installtion of WF solution.Go with following checkings.
1.Check is it correctly installed in the GAC?
2.Does your assembly version match the strong name info in the workflow.xml file?
3.Carefully check every step of your deployment.

Error Occurred: This means you are one step ahead of the previous error Your workflow has launched but found a problem somewhere along the way. Take a look at the logs mentioned above and if you have used the LogToHistoryList activity often enough this can be a nice indication of where to start debugging in your code. otherwise just start at the beginning. This will give you a relatively detailed error description in Visual Studio and you can retrace your steps to see where things went wrong.

Forms: If you are using Infopath Forms for your tasks, and you are experiencing problems, check that they are in the correct folder in your feature (C:\Program Files\Common Files\Microsoft Shared\web server extensions\12\TEMPLATE\FEATURES). Also make sure that the form is deployed with Security Level ‘Full Trust’.
(via the ‘Design Tasks’ Pane, ‘Design Checker’, Change Compatibility Settings’, ‘Security and Trust’, Select ‘Full Trust’.)
When publishing the form to a network location, also make sure the url in the second box (‘If users access the form template from the published location blabla…’) is left empty.