No, I don't have any reference to an MDG file.
Even if I remove the MDG, regenerate the MDG using Sparx 14 and import it, I still can't see the MDG in the resources window.
NB:
Using the "Technologies / Manage" option, there is a button '"Remove" that is activated for our technology.
And from Resources Window I can still import the MDG => It gets imported and activated, but it is still not visible in the Resources window.
For checking the existence of the MDG in the database: SELECT * FROM t_document where DocType = 'TECHNOLOGY' and DocName ='TechnologyName'