As the title says, I'm trying to deploy some code and metadata from a sandbox to another. The deployment compiles successfully, and the tests pass too, but the deployment fails with the "Code coverage error" message.

The weird thing is that no coverage errors are shown. Usually it displays to the user which class is missing coverage, and how many lines are covered by the tests that were run.

[![no classes are shown](https://i.stack.imgur.com/Vhhmz.png)](https://i.stack.imgur.com/Vhhmz.png)

What can be causing this?

Note: both environments are on API 44 (Winter '19).
This is a single-language org, so the interface is in portuguese. But as you can see, no classes are listed.