This is an internal-only error message and should have been re-worked before being displayed by the product. Please file a Tech Support ticket with a model snippet so that it can be fixed. Thanks.
The message is saying that you are trying to assign an attribute of size [1x2] with a value of size [4x2]. In SimEvents attributes have fixed sizes determined during compile. Somewhere in your model you are assigning an attribute (say "A1") with a [1x2] value and so the product records that the dimensions of A1 is [1x2] and will error out if any other block attempts to read/write a differently sized value from A1.
