“Ignore fail and proceed next time” option is a solution for task failing, because of some Jira issue (e.g. active sprints missing).
User have task being created every Monday, but make some changes on Friday. The following Monday Scheduler fail to create task. Currently user have to "fix" SI, only then task can be created next Monday. After check this option trigger will ignore such fails, and 'try' to create task next time - since the condition might have changed and task might be created without any edition of SI.
“Ignore fail and proceed next time” option you can set on the first step of creation Scheduled Issue Wizard (1).
As you can see the creation of SI is failed (2).
But the SI is still active (3) and will try to create task on next planned execution.