can i re-issue my encryption key

I switch computers recently and did not transfer my encryption key. Is there a way to get my key reissued to open the encrypted forms i have

Unfortunately, it's not possible to re-issue the encryption key as it's unique, you can't re-issue the same key, and even if you did, it will not work with the old submissions that were encrypted using the old key. 

If you have any access to your old computer, you can simply copy the key over to the new machine and it should work fine.