Column names must contain UTF-8 encoded from blob inventory

Hi Mikeblakeuk1, 

Column names will need to be fixed before the data is stored as parquet delta. These rules exist to ensure Fabric is able to determine exactly what table you are trying to reference. 

For example, if we pretend we have a table called "this.table" Fabric would interpret it as a table called table in a schema called this, which would result in it not being able to find the table at all. 

Hello Mikeblakeuk1,

Azure Blob Storage Inventory outputs columns like Last-Modified, but Microsoft Fabric Lakehouse only accepts letters, numbers, and underscores for column names.

Hyphens will cause the InvalidColumnName error when you try to load into a table. The preview can still show the data, but the table creation step enforces stricter rules.

You’ll need to rename those columns first, for example Last-Modified → Last_Modified.

Docs:
Troubleshoot Lakehouse issues for Microsoft Fabric Data Engineering
Azure Storage blob inventory