When attempting to save a Custom Data List that includes Filters, the error: There was an error deserializing object of type Blackbaud.AppFx.WebShell.WebUI.Contracts.AdHocQuery.AdHocQuerySaveDataListRequest. The value "cannot be parsed as the type 'Int32' is received. If the Data list is saved without any filters, and then reopened, it can be saved with the Filters.
We are currently evaluating this issue and will update this article when we have more information. As a work around you can first save your data list with no filters. Once saved, it can then be successfully edited to add filters.