Solution
It is likely that you have an invalid encryption string configured in the systemstate.secrets.encryptionKey field of the Helm chart you used most recently to deploy your SystemLink Enterprise. All encryption keys in SystemLink Enterprise must be plain strings that are exactly 32 bytes long and contain only alphanumeric characters (A-Z, a-z. 0-9). Here are 2 different methods to generate a valid (and random) encryption key:
The result will look like this: G6h8K2mN9pQ1rT4uX7yZ2aB5dE8gH1jm