Yes, the validation became more strict with newer versions of openLCA, and thus more things are found (although unit duplicates are already in the validation since some time) - these are not very critical, and therefore shown as warnings, but can cause confusion if you use a different Mg units in different places in your model, for example. You can, if you want, edit the units to get rid of these duplicates, by renaming, or, if you are certain, by deleting on of the duplicates (that is not used at all, e.g.). These duplicates are often simply mentioned in synonyms. So you have ton, and Mg, as units, and Mg mentioned as synonym for ton.
Edit: this is not linked to the possibility to export a database.
