Last Updated On: 2025-09-01 04:31:51 -0400

This error almost always means that Rails cannot cannot decrypt your credentials because the master key is missing or wrong.

It should be note that when you are in development mode Rails 8 will DEFAULT to using an environment variable over the locally stored master key WHICH IS NOT WHAT YOU WOULD EXPECT.

Execute a:

UNSET RAILS_MASTER_KEY

before you do anything.

After that if it is still a problem then follow the tips in my Kamal posts.