I'm getting verification code "(null)" on my iPad when I try text forwarding from iphone

Ahh I have the same problem! Obviously not one of the popular problems on these forums since I don't see a lot of posts. So for me, text forwarding was working perfectly but now experiencing same issue after having to erase settings on iPhone to fix another issue from a wonky app. Text message forwarding option shows up on iPhone with toggle switch for each device, but when attempting to connect on Mac, message app opens, but no popup is displayed. When attempting to connect on an iPad it gives: "...enter the code "(null)" on your iPhone now."

I've tried logout/login on iMessage all around. Nothing.

I've tried logout/login to iCloud login all around. Nothing.

I've tried resetting network settings on iPhone. Nothing.

(Power cycled each device in between logout/logins.)

Tried disabling bluetooth on all devices and repeating. Nothing.

Tried disabling wifi (on iPhone only) and bluetooth (all devices) and repeating. Nothing.

Continuity is very much working on the devices as Copy/Paste, Phone Calls, etc. are all function perfectly.

Running Console on Mac when attempting to pair devices (the enable text message forwarding from iPhone) shows a very clear (and consistent) "Decryption Error" from the identityservicesd library, and public/private decryption failed 😟 (yes it includes a frowny face, which is really how I know I'm in trouble). It seems like a key/pointer/something changed/corrupted/who knows, as a result of the reset and now I'm not sure how to get the devices to acknowledge the change or at least look in the same place.

Is there a way to reset/update public/private keys for devices for this type of activity? I'm reluctant to start randomly deleting keys from the keychain access (I think I read someone suggested that somewhere). Since I'm a sad newbie to the whole Mac stuff I'm not really sure what to do anymore short of full wipe of everything. Not even sure that would solve the problem if restoring things from backups. Help!

All right solved my own problem. Discovered that if I take an old text message thread that was working (when previously paired) then attempt to send a message I (obviously) get a send failure. However, this appears to clear/reset/jog the handshake such that when sending a text message forwarding request from the iPhone it now can successfully decrypt the key pairs (i.e. shows the pairing code instead of a "(null)". I had to do this on each device but they are all talking to each other successfully now. Glad someone thought to add in some reset logic at some point, but this handshaking should probably be better tied in to Continuity in future builds (similar to wifi calling etc.)

This worked! After working on this (always getting "null" as my verification code for re-setting up text message forwarding) for a month--resetting network settings, turning iMessage off and on, rebooting both devices, waiting and trying again, etc etc--I went in to my iPad message history and replied to an old SMS text from when text messaging forwarding was working. Then I tried again to set up text messaging forwarding from my iPhone to iPad (which had been set up previously)and I got a real code, not the "null" code I have gotten for the last month when trying to reactivate.

Well... You are correct sir, it worked! Certainly appreciate your discovery, and I have to say this is the ONLY solution that worked after many, many different attempts, iPhone, iPad, rMBP reset operations, etc.

Thank you!

Have a great day!

I recently did a system update and stopped receiving my texts. Kept getting "(null)" verification code when trying to enable text message forwarding. After hours trying logging in logging out, I message, and anything else I could think of. I read a post and sent a text to an old contact that had an Android device. It came back not delivered. I then went back to enable my text message forwarding and it sent me an actual code. Receiving and sending all my texts again.

Thank you so much for posting this....I had done a system reset on my phone and lost all forwarding connections. Tried all day to get it to work again. Finally saw your post, and your trick worked.

Thanks a lot! The only method that really worked. Kudos!