Error Code: Mashup Exception Expression Error

Hi DLAMANSAW12 

Thanks for using Microsoft Fabric Community.

Apologies for the inconvenience.

The error message points to a type mismatch issue during data transformation within your Dataflow Gen2 mashup document.

Mashup Exception Expression Error: This indicates an error in the M code used for data transformation within the mashup document.
Couldn't refresh the entity...: The refresh process for the entity (likely a table) failed due to the M code issue.
Expression.Error: Failed to insert a table.: The specific error lies within an expression attempting to insert a table.
InnerException, We cannot convert a value of type List to type Text.: The core problem is that the expression is trying to insert a list of values (data type List) into a column expecting text.

Review Your M Code: Carefully examine the M code within your mashup document, particularly sections that involve data manipulation and table creation. Look for lines where you might be trying to insert a list of values into a text column. You should be able to identify the specific cause of the type mismatch and apply the appropriate solution.
Focus on Column Definitions: Pay close attention to how columns are defined within your tables. Make sure the data type of each column accurately reflects the kind of data it should hold. If a column is intended for text values, it shouldn't be defined as a list type.
If you are using Text.From to join list elements, it might be causing the issue. Switch to Text.Combine, which is specifically designed for list concatenation into text.

I hope this information helps. Please do let us know if you have any further questions.

Thanks.