Hello @Thomas Michielsen​ , this error seems to occur when you may have created the table yourself.

You must use publish_table() to create the table in the online store. Do not manually create a database or container inside Cosmos DB. 

publish_table()  does that for you automatically.

If you create a table without using 

publish_table() , the schema might be incompatible and the write command will fail.

Saw from the link - https://learn.microsoft.com/en-us/azure/databricks/_extras/notebooks/source/machine-learning/feature...

Can you please confirm if you are using publish_table() ?

Thanks & Regards,

Nandini