Question

Is it possible to prohibit Manual Review operators from closing a task with rule errors or unverified symbols?

Answer

It is not possible to prohibit operators from closing a task if there are rules or uncertain symbols. However, it is possible to re-route the documents to the Manual Review again with the IF activity where it can be checked if there are errors/uncertain symbols in documents of a transaction:
 

Additional information

AU Help: Condition (IF) activity

EU Help: Condition (IF) activity

US Help: Condition (IF) activity