Concordance Search not working: "An error has occurred while using the translation provider <TM name>: object reference not set to an instance of an object"

While translating in Studio 2019 (SDL Trados Studio 2019 SR2 - 15.2.8.3007), when running Concordance Search, it fails and the following error message appears:

An error has occurred while using the translation provider <TM name>: object reference not set to an instance of an object

This seems to be happening in all projects, and also independently of whether it is a GroupShare or a Studio project.

The TM is active and accessible. I can see the Translation Result window in the project.