Reversing a voided check isn't a functionality supported in Acumatica. Voiding a check is designed to be a one step process, which cannot be reversed. If Voided Check is released/ closed the only way to fix/rectify the situation would be to create and write a new check.

@eray you will need to issue a new check to replace the voided check, as @MinushaWeerasuriya76 stated, it’s not supported.  I definitely learned that the hard way too 

Thank you for the information!