You may find that your catalogue is not displayed in Lengow. This could be due to a broken connection between your shop and the plugin.
Why is the connection between my shop and the plugin broken?
The plugin's indexing url for retrieving the product catalogue is located in your shop's Front Office. Any deactivation, even temporary, prevents the plugin's urls (feed_url, cron_url and toolbox_url) from being used.
What should I do?
Check that your Front Office is fully accessible and running at the time of indexing. Otherwise the indexer and the Lengow solution cannot communicate with the plugin and will return 404 errors.
Similarly, any virtual shop created specifically for Lengow must have an access point in the shop's Front Office so that the catalogue can be properly indexed in Lengow.