I have created a Workflow in SP Designer and attached to one list. It's getting the error "Workflow was cancelled by System account and failed on Start". It's happening for recently created workflows in this site collections and old workflows are working fine. If I create a new workflow in this site collection I get the issue. If I create a new workflow in other site colections those are working fine. Can anyone help on this issue?
You always get an error message in the ULS log. I just documented on how you can get the error message easily: https://engineerer.ch/2019/01/04/how-to-find-errors-in-the-sharepoint-uls-log/
I suggest to publish your workflow again as a non-system account through SharePoint Designer. That helped solving a lot of workflow related errors.
Does the issue exists in SharePoint 2010 platform workflow or SharePoint 2013 platform workflow?
don't start the workflow with system account, Log in and start the workflow as a different user (rather than System Account) to test.
Clear SharePoint Designer cache and compare the results: