If you use Coveo with Sitecore, a routine database restore can quietly break your search and the error message won’t point where you think. Here’s a quick post-mortem of a real hiccup, what caused it, and the two-minute fix.
Sitecore stores a set of encryption keys per database in [dbo].[Properties] under the key WEB_ENCRYPTIONKEYS. These keys are used to encrypt/decrypt various secrets at runtime, including credentials used by integrations like Coveo.
After updating the encryption keys, the error disappeared and Coveo calls resumed working. Find out more about the root cause and the quick fix in the original post by José Neto.