When your current AX4 or AX2009 environment has more than 5 financial dimensions, you need to ensure you setup the AX2012 system so the existing data can map over to the new system.
There are eight extended data types that need to be changed in AX2012 to ensure the field mappings correctly configure to transfer the data between systems as part of an upgrade. These extended data types are: DEL_COSAllowDimensions, Dimension, DimensionAllocation, DimensionCriteria, DimensionKeepFromTransaction, DimensionPriorit, MandatoryDimension and XMLMapDimension.
For each of the extended data types you need to add the necessary Array Elements to ensure they cover the number of financial dimensions contained in the source system. The naming and labeling of the dimensions is not important as these fields are not used with the standard AX 2012 dimension structure, this is just for the purpose of upgrading the data from the earlier versions.