macOS Sierra Install/Upgrade Problems

I installed the beta of macOS Sierra and have not been able to upgrade to Hazel 4 on it. Hazel 3 appeared to be working normally, but if I try to either upgrade or install Hazel 4 I get the following error:

I have tried:
If anyone has any advice I'll happily try anything, I just want Hazel installed again!

I have tried:
- Restarting the computer
- Updating the beta
- Uninstalling Hazel 3 (so as to do a clean install of Hazel 4)
- Downloading a new copy of the DMG
If anyone has any advice I'll happily try anything, I just want Hazel installed again!
