Convert your settings.yaml (used by LOOT v0.11.0 and earlier) to a settings.toml (used by LOOT v0.12.0 and later). Your settings.yaml can be found in %LOCALAPPDATA%\LOOT\, which LOOT's "Open Debug Log Location" menu option opens, and the settings.toml goes in the same directory.

Note that the download link that appears above after converting YAML does not work in Internet Explorer or Edge. Users of those browsers will need to copy the content of the TOML text box into a settings.toml file they create themselves, or use a different browser.