Failed on Start (Workflow was canceled by System Account.)

For your issue, I recommend to follow the steps as below:

1. Clear SharePoint Designer cache: How to Clear Your SharePoint Designer 2010/2013 Cache
2. Deactivate all "Workflow" features at the Site Collection level.
3. Enable all "Workflow" features at the Site Collection level.
4. PSCONFIG (Not Necessary) (or run the SharePoint 2010 products configuration wizard)
5. Delete the bad workflow.
6. Create a new workflow on the list with an valid user.