Question regarding data encryption

Until recently we used both LTO3 and LTO 4 tapes in our LTO4 drives. Last week we enabled encryption on these drives.Now we can only write to the LTO4 tapes.I understand that LTO3 tapes do not do encryption but, I didn't realize that the drives would not write to these tapes at all.We have ordered a new supply of LTO4 tapes but, in the meantime, is there any way to write to the LTO3 tapes without disabling encryption?

Networker version 7.5.1