Cannot add column to table in Power Query because "Database is in restricted mode"

[studentofdata]

I imported a table of data into Power Query but cannot create a new column. When I try to split the column or do any transformation, I get this error message:

DataSource.Error: Microsoft SQL: Database 'SANDBOX' is in restricted mode. Only the database owner a...

Why am I getting this error and is there any way around it? I was under the impression that I've loaded the data and have the freedom to do any transformations. I am not making any changes to the table in MS SQL Server so I don't understand why this message is appearing.

All I'm trying to do is split a date&time column into two seperate columns (i.e., one column for date, another column for time).

[amitchandak]

@studentofdata , I doubt this table is in direct query mode ,

check https://docs.microsoft.com/en-us/power-bi/transform-model/desktop-storage-mode

[studentofdata]

Hi @amitchandak, 

Thank you for your help.

The storage mode of my tables already says "Import". Is there anything else I should do?