Hello, I tried to add a table through the webpage and get an error that the table already exists, but it isn’t showing up in the list of tables. Any possible reasons for this?

I met the same error. It’s because your table wasn’t created successfully due to some error. But the table’s metadata is stored in zookeeper which gives you such error when you try to create the table again. The solution I tried and worked is you can delete the table through API and then you can create the table again.

Also you can check the controller logs for a more precise trace..

check if schema is created and you can delete it then recreate the table