After some modification of categories I get this error on the category page in frontend not admin:
Item (Magento\Catalog\Model\Product\Interceptor) with the same ID "160" already exists.
Magento Version 2.1.6
I hope somone can help, thanks!
You can solve this issue using Delete product with id 160 from your catalog product backend.
Because Product with same name already exist and url rewrite is not possible for same name Product. I have faced this type of issue when i had import product using csv.
If Admin Panel Product page not display grid and display popup at that time you have to delete product id with 160 from Database.
Go to your database,
find catalog_product_entity table and delete entity_id with 160.
Run php bin/magento indexer:reindex command.
If issue solved, click Kudos and Accept as Solution.
Does doing this delete the product from Magento entirely meaning you have to re-enter the product? Or does the product still exist after deleting from the catalog_product_entity table and it simply fixes the problem?
I just tried this on. I found the ID in the catalog_product_entity table, and it was referring to a different product. I deleted that row, and reindexed. Problem still exists, and also the other product it was referencing is now deleted from Magento. So this solution doesn't seem to be working for me.