TypeError | Error Message: Cannot call method "join" of undefined" error.
This is a case where multiple saved searches are added in the configuration. When the inventory export flow runs, it produces this error.
This is not an issue as much as it is a required parameter in the configuration of saved searches. Here you need to have internalid as a search column. If it is missing, then the framework will produce the error. Please review the below content. Please verify saved searches.
"The Inventory Export flow expects Internal ID in the search results. As this field is missing in the Search, the back end code is returning null for one of the search ids, and join operation on the search records is failing because of this."