We cannot convert the value "” to type List.

[Sagejah9]

Hi community members, 
I am encountering this problem when I am refreshing my queries. This has come up on a query that came from an API that I converted from a list to a table. However, after converting the list to a table I added a column to the table from another table by merging on a key column but the newly added column(date type)  has null values. How can I solve or work around this?

[Anonymous]

@Sagejah9 

The error message shows that it can't convert null value, perhaps you can try to replace these null value to a default value before your operation. So in your case, try replace the null with a suitable date then try again.

Paul Zheng _ Community Support Team
If this post helps, please Accept it as the solution to help the other members find it more quickly.

[amitchandak]

@Sagejah9 , In the blank row, you do not bank/null you have space " " , first replace space with null in power query and then try

[Sagejah9]

@amitchandak 
it actually says null in the rows under the column that I have added. 

[Sagejah9]

@amitchandak I am also working with the May 2020 version. When I disable the load on the new merged query, it refreshes fine so I know it's a problem with the null values in the column. Not understanding why it should affect it if it's converted to a table. I need that column in the same table to do calculations.