Build Data Table Error (DataTable could not be read)

Question

As seen above, there’s some error with the building of data table… Any help here?

Error message is as follows: Creating dtData2: Type ‘UiPath.Core.GenericValue, UiPath.System.Activities, Version=20.4.0.0, Culture=neutral, PublicKeyToken=null’ is not allowed here. See https://go.microsoft.com/fwlink/?linkid=2132227 for more information.

2nd upload as per requested:

Answer 1

You might be using a .xaml file from a newer version of Studio. The BuildDataTable seems to be picky about that.

I encountered that mysterious crash on our production system after some third party developers made some code changes. I noticed the version of UIPath generic object in my crash screen was 19.10.x.x, and I know our Production and Test/Dev systems are on v18.x.

I suspected they sent us code developed in a newer version of Studio, or copied and pasted remotely from their Studio to ours and it happened to work (at least the pasting). I got a complaint from the users that the robot didn't work so they'd just do it manually until it could be fixed.

To "fix", edit the .xaml in Studio. Find the Build Data Table in the Activities and created a new code block. Since the Build command is so simple, needing only the output dt field, that might be the easiest option. I reran it in debugging with the new "BuildDataTable" acitivity and it didn't throw the exception. [I probably could've downgraded the genericvalue version number in the .xaml file, but I was already in Studio.]

You can also use "findstr" to search for the BuildDataTable commands from the .xaml file. The findstr or egrep command can show you the version of the genericvalue UIPath is trying to stuff into the empty datatable on creation:

 <ui:BuildDataTable DataTable="[DetailDT]" DisplayName="Details Data Table"
xs:element name=&quot;Change_x0020_Type_x0020_Index&quot; 
... 
msdata:DataType=&quot;UiPath.Core.GenericValue, UiPath.System.Activities, Version=19.10.1.0, 

One of the nicer "features" of UIPath is their use of a sort of open format .xaml file for all the code storage. Using findstr or egrep has really helped find hidden problems spread across our large collection of folders. Their xaml is not as easy as merging code written in autoIt3 or AutoHotKey, as they have graphic screen size elements and block number tags embedded in it, but at least all the graphical code blocks aren't completely locked away in some compressed or OLE format as would be tempting for software that works (only?) on Windows.

Answer 2

Check your UiPath.System.Activities version. I had the same error with a DataTable containing another DataTable as a column. Basic datatypeas as string and int were no problem, but a DataTable threw the error. I updated UiPath.System.Activities to 20.10.4 (from 19 something) and it worked after that. Also tried with 21.10.4 and that works as well.