I've encountered a big issue on workflow. I designed a very simple workflow with Action "Send Email" on SharePoint Designer 2010 for email testing, as well as workflow process. All things were configured correctly. I created a Custom list and then created a new item. The workflow started, however, it was stopped immediately.
From workflow history, there are two events: - <Name of workflow> failed to start. - <Name of workflow> was cancelled by System Account.
I've tried to change Web Application application pool account and then reset IIS several times but it still doesn't work.
I don't know exactly what happens but in the past when testing on SharePoint 2010 RTM, I didn't have any issues. Currently I'm using SharePoint 2010 Service Pack 1.