Object reference not set to an instance of an object, Sharepoint list Output Tool

[Nicolasq]

Hi all,
I'm trying to upload data from Alteryx to a SharePoint List. I'm trying to use the Sharepoint list Output tool to do this with the following configuration:

When I run the flow, the error Object reference not set to an instance of an object appears.
In the beginning, I thought it could be data types that weren't matching with the Sharepoint list, but it wasn't that.
I have 3 date fields that I transformed to UTC format, but it didn't help.

I tried changing the data types back into strings because I read that the error that I have appears when you have nulls in your data (https://community.alteryx.com/t5/Alteryx-Designer-Discussions/Object-reference-not-set-to-an-instanc...), but it wasn't that.  

Any help would be appreciated.

Thanks

[Nicolasq · Accepted solution]

I fixed it, I had created a "Choice" data type on SharePoint and that was creating the problem, I changed it to a "single line of text"

Note aside: You can have nulls in your "date" data type in Alteryx and upload them into a SharePoint list.