Build Data Table Error (DataTable could not be read)

Same problem here, in my case I had a DataTable that had a column of DataTables (of type System.Data.DataTable). To replicate the error, you can try to create a BuildDataTable activity and make any column of that type, when you save it and try to open it again the error should appears. This can’t be something torelable, I’ll open a support request for UiPath to solve it.

Found a temp solution: Uninstalling Windows Update version kb4565511 :slight_smile:

This is a big problem for our running robots. Proactive information from UiPath would be very helpfull.

This issue was never noted earlier and has been occurring in recent times only. The datatable type should not be GenericValue. Please change it to String/Object.

Can you share details on what the structure of this data table is?

our two projects that run on robots are not working due to this issue. we are stuck here. is there any solution ?

Hi, i think we have the solution.

The issue cause for the Windows Securty Update on .Net Framework (you can see the details here: DataSet and DataTable security guidance - ADO.NET | Microsoft Learn)

With this update, only suitable primitive data types are allowed when creating datatable objects from files such as xml or xaml. This means that we cannot use the data types in the UiPath library directly in the build datatable activity.

If you want to use these data types, you must first delete these data types from the build datatable activity in the xaml file. Then you have to add these data types to the datatable with invoke code (as I have shown below).

io_myDataTable.Columns.Add(“Window”, GetType(UiPath.Core.Window))


Hi ! I got the same problem. In fact it is very EASY. You just dont have to modify the 2 default columns. But you need to add new columns.
Then, concerning the 2 default columns, just DELETE THEM. And ADD your own columns :wink:


Can you share your Studio version? If you have a lower version than 20.10, can you update to 20.10 and let me know if the issue persists?

@alexandru FYI