Older System - New Version Keypad?

You will have to get a whole new system. Nothing on the new simplisafe will work with the older one except the video doorbell and the interior camera. They do have i think up to 40% off on the purchase of the new ss, i think ypu just have to turn in your old one.

The old system does not use encrypted signals and the new system does.  Thus the old system thinks the new signal is gobbledygook and the new system thinks the old signal is invalid.

According to the website, for what it's worth, you can still buy a replacement keypad for the SS2 system.

https://simplisafe.com/alarm-sensors  Then click on the original system. Looks like they are advertising 15% off.