We have some intermittent issues with import actions that give up the following error (in pic)
The target module had a new line item introduced which was on a subset of the same list as the entire module.
The module was based on Subset 1 (applies to).
The new line item was based on Subset 2 (applies to).
Subset 1 and Subset 2 are subsets from the same List A.
The action fails saying the dimensions in the target module do not match the import definition. The action causing the issue was a pre-existing action on a different line item in the module which has no direct link to the new line item which was introduced.
Also, I have tried to open up this pre-existing action, set the new subset as 'Not Applicable to this Import' and then RUN it - it still leads to the same error.
The problem seems to go away only when you remake the entire action from scratch. This would be an issue as it restricts us from modelling without having to worry about all the pre-existing actions/integrations.
I don't think this is an issue here. Once you import data into a module, Anaplan remembers the import definition based on the mapping. You will have to redefine the import definition the moment you change the module.
Here in your case adding the new line item.
Also, always remember while importing into the same module, with changes in the mapping, Anaplan does not always create a new import definition. It is recommended to delete the previously defined import definition and create a new one.
@sandeep_bk is right, everytime you create a new line item that you want to import to, you can reuse the existing import action but you do need to remap by doing 'edit --> Line item tab'.
Another thing that i would like to point out is that it's not best practice to have subsidiary views for input fields. Ideally all the line items would have the same lists combination as the module, but it's very hard to do so for calculation line items.
However we should build a separate module for input line items which share the same lists combination. Off the top of my head, one reason i can think of why this is a bad idea is the severe limitation of Filtering. You'll see in the screen shot below that the line item can only refer to itself for filtering purpose.