Error - Potentially on NULL int fields.

[jfontestad]

I also have the following error:

Error in clrCall(sqlDataHelper, "Fetch", stride) : 
  Type:    System.ArgumentException
Message: Cannot widen from source type to target type either because the source type is a not a primitive type or the conversion cannot be accomplished.
Method:  Void InternalSetValue(Void*, System.Object)
Stack trace:
   at System.Array.InternalSetValue(Void* target, Object value)
   at System.Array.SetValue(Object value, Int32 index)
   at rsqlserver.net.SqlDataHelper.Fetch(Int32 capacity) in C:\Users\Ruaridh Williamson\Documents\GitHub\rsqlserver\src.nocompile\rsqlserver.net\src\SqlDataHelper.cs:line 171

Coming from fields of int data-type. but are NULL.

[ruaridhw]

Can you provide some context about what caused the error? Here is some documentation on producing reproducible examples that can help diagnose problems you're facing. If you can't provide a code chunk that reproduces the error we can't help!