System Admin saved recurring transaction as void and I cannot undo that. Can I change a recurring template back to the way it was before it saved it as a voided check?

I'll make sure that this gets resolved for you, kathrynhollis195.

Right now, there isn’t an option to un-void a transaction in QuickBooks Online. Once a transaction is voided, it can only be recorded back by recreating it.

You can use the Audit Log tool to get the details of the voided transaction. You can visit the How to undo a voided transaction article for the detailed step by step process. 

Keep in mind that the amount on a voided transaction is always 0. In order to show the details of the original transaction, kindly select the information on when it was added or edited.

As for your other concern, yes, you can change back the recurring template by just clicking the Edit button. 

For future reference, you may find below articles helpful:

• Learn about the audit log
• Record a customer payment

Drop me a comment if I can do anything else for you when recreating a transaction. I'd be around to assist. Have a great day!