Column names must contain UTF-8 encoded from blob inventory

[Mikeblakeuk1]

Hello,
 
f you set up blob inventory, you can't import the parquet into Fabric Lakehouses.
 
In Azure Storage
Setup Blob Inventory, with date fields.
 

Wait 24 hours
Download the parquet files
 
In Fabric
In a Lakehouse
Upload the file
Load to Tables, New Table
  

 
Expected: It loads the data
 
Actual: Error
Server Error.
Message : Invalid column name(s). Column names must contain UTF-8 encoded Unicode word characters and can be a maximum of 128 characters long. Unicode word characters include letters of any case and their nonspacing marks, punctuation connectors like the underscore(_), and decimal digits, but no space characters are allowed.
Error Code : InvalidColumnName
Error source : 1
Activity Id (Failed Request) : 4dc4de45-e218-4f94-9bd9-5ee067366b35
Client Session Id : 27e1b3bc-7e9c-4880-b764-7d527e6c042f
Activity ID (Initial Request) : ec4a448e-5e47-447b-8198-4065850c7036
User session Id : f04a022f-c25c-4289-a42d-cd7f97a20cac
 
Do we know what column is causing the issue? I assume -
a) Can Microsoft Storage export with valid parquet column names?
b) Can Microsoft Fabric import and handle column with bad chars.
 
we don't really want a pipeline to process the file, fixing the column. it should just work
 
Note, the preview appears to work.
 

[tayloramy · Accepted solution]

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. 

[v-echaithra]

Hi @Mikeblakeuk1 ,

May I ask if you have resolved this issue? Please let us know if you have any further issues, we are happy to help.

Thank you.

[v-echaithra]

Hi @Mikeblakeuk1 ,

Thank you @Olufemi7 , @tayloramy  for your inputs.

We’d like to follow up regarding the recent concern. Kindly confirm whether the issue has been resolved, or if further assistance is still required. We are available to support you and are committed to helping you reach a resolution.

Thank you.

[Olufemi7 · Accepted solution]

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

[tayloramy · Accepted solution]

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.