Here’s an issue that’s come up for us a couple of times while doing AX 2009 to Dynamics 365 for Finance and Operations upgrades. The DMT toolkit provides an entity to migrate Unit Conversion data from AX2009 to D365. However, an issue is encountered when this data is imported into D365 using the default settings. There seems to be an issue with the entity in D365.
What’s the issue?
Here is the scenario: In AX2009 the unit conversion is: “From unit” * “Factor” = “To unit” An example would be FT * 3 = YD 
However, upon loading the data, the result we get is unexpected. The factor has switched the “From unit” to the “To unit”. This creates inaccurate conversions. 
Workaround: Modify the mapping during import by mapping the “From unit” in the Source to the “To unit” in the Staging and vice versa. This will ensure that the conversions are correct. 
The result looks as expected. 
The same applies to the Product Specific Unit conversions entity.